Rust 1.54.0 lints (#2483)

## Issue Addressed

N/A

## Proposed Changes

- Removing a bunch of unnecessary references
- Updated `Error::VariantError` to `Error::Variant`
- There were additional enum variant lints that I ignored, because I thought our variant names were fine
- removed `MonitoredValidator`'s `pubkey` field, because I couldn't find it used anywhere. It looks like we just use the string version of the pubkey (the `id` field) if there is no index

## Additional Info



Co-authored-by: realbigsean <seananderson33@gmail.com>

consensus/state_processing/src/per_block_processing/block_signature_verifier.rs

@@ -244,10 +244,10 @@ where
             .iter()
             .try_for_each(|attester_slashing| {
                 let (set_1, set_2) = attester_slashing_signature_sets(
-                    &self.state,
+                    self.state,
                     self.get_pubkey.clone(),
                     attester_slashing,
-                    &self.spec,
+                    self.spec,
                 )?;
 
                 self.sets.push(set_1);
@@ -280,11 +280,11 @@ where
                         get_indexed_attestation(committee.committee, attestation)?;
 
                     self.sets.push(indexed_attestation_signature_set(
-                        &self.state,
+                        self.state,
                         self.get_pubkey.clone(),
                         &attestation.signature,
                         &indexed_attestation,
-                        &self.spec,
+                        self.spec,
                     )?);
 
                     vec.push(indexed_attestation);
@@ -307,7 +307,7 @@ where
             .iter()
             .try_for_each(|exit| {
                 let exit =
-                    exit_signature_set(&self.state, self.get_pubkey.clone(), exit, &self.spec)?;
+                    exit_signature_set(self.state, self.get_pubkey.clone(), exit, self.spec)?;
 
                 self.sets.push(exit);
 
@@ -323,8 +323,8 @@ where
                 sync_aggregate,
                 block.slot(),
                 block.parent_root(),
-                &self.state,
-                &self.spec,
+                self.state,
+                self.spec,
             )? {
                 self.sets.push(signature_set);
             }

consensus/state_processing/src/per_block_processing/is_valid_indexed_attestation.rs

@@ -44,7 +44,7 @@ pub fn is_valid_indexed_attestation<T: EthSpec>(
                 state,
                 |i| get_pubkey_from_state(state, i),
                 &indexed_attestation.signature,
-                &indexed_attestation,
+                indexed_attestation,
                 spec
             )?
             .verify(),

consensus/state_processing/src/per_block_processing/process_operations.rs

@@ -177,7 +177,7 @@ pub fn process_proposer_slashings<T: EthSpec>(
         .iter()
         .enumerate()
         .try_for_each(|(i, proposer_slashing)| {
-            verify_proposer_slashing(proposer_slashing, &state, verify_signatures, spec)
+            verify_proposer_slashing(proposer_slashing, state, verify_signatures, spec)
                 .map_err(|e| e.into_with_index(i))?;
 
             slash_validator(
@@ -202,11 +202,11 @@ pub fn process_attester_slashings<T: EthSpec>(
     spec: &ChainSpec,
 ) -> Result<(), BlockProcessingError> {
     for (i, attester_slashing) in attester_slashings.iter().enumerate() {
-        verify_attester_slashing(&state, &attester_slashing, verify_signatures, spec)
+        verify_attester_slashing(state, attester_slashing, verify_signatures, spec)
             .map_err(|e| e.into_with_index(i))?;
 
         let slashable_indices =
-            get_slashable_indices(&state, &attester_slashing).map_err(|e| e.into_with_index(i))?;
+            get_slashable_indices(state, attester_slashing).map_err(|e| e.into_with_index(i))?;
 
         for i in slashable_indices {
             slash_validator(state, i as usize, None, spec)?;
@@ -254,7 +254,7 @@ pub fn process_exits<T: EthSpec>(
     // Verify and apply each exit in series. We iterate in series because higher-index exits may
     // become invalid due to the application of lower-index ones.
     for (i, exit) in voluntary_exits.iter().enumerate() {
-        verify_exit(&state, exit, verify_signatures, spec).map_err(|e| e.into_with_index(i))?;
+        verify_exit(state, exit, verify_signatures, spec).map_err(|e| e.into_with_index(i))?;
 
         initiate_validator_exit(state, exit.message.validator_index as usize, spec)?;
     }

consensus/state_processing/src/per_block_processing/signature_sets.rs

@@ -257,7 +257,7 @@ where
     let domain = spec.get_domain(
         indexed_attestation.data.target.epoch,
         Domain::BeaconAttester,
-        &fork,
+        fork,
         genesis_validators_root,
     );
 
@@ -494,7 +494,7 @@ where
         pubkeys.push(get_pubkey(pubkey).ok_or_else(|| Error::ValidatorPubkeyUnknown(*pubkey))?);
     }
 
-    let domain = spec.get_domain(epoch, Domain::SyncCommittee, &fork, genesis_validators_root);
+    let domain = spec.get_domain(epoch, Domain::SyncCommittee, fork, genesis_validators_root);
 
     let message = beacon_block_root.signing_root(domain);
 
@@ -513,7 +513,7 @@ pub fn sync_committee_message_set_from_pubkeys<'a, T>(
 where
     T: EthSpec,
 {
-    let domain = spec.get_domain(epoch, Domain::SyncCommittee, &fork, genesis_validators_root);
+    let domain = spec.get_domain(epoch, Domain::SyncCommittee, fork, genesis_validators_root);
 
     let message = beacon_block_root.signing_root(domain);
 

consensus/state_processing/src/per_block_processing/verify_attester_slashing.rs

@@ -33,9 +33,9 @@ pub fn verify_attester_slashing<T: EthSpec>(
         Invalid::NotSlashable
     );
 
-    is_valid_indexed_attestation(state, &attestation_1, verify_signatures, spec)
+    is_valid_indexed_attestation(state, attestation_1, verify_signatures, spec)
         .map_err(|e| error(Invalid::IndexedAttestation1Invalid(e)))?;
-    is_valid_indexed_attestation(state, &attestation_2, verify_signatures, spec)
+    is_valid_indexed_attestation(state, attestation_2, verify_signatures, spec)
         .map_err(|e| error(Invalid::IndexedAttestation2Invalid(e)))?;
 
     Ok(())

consensus/state_processing/src/per_block_processing/verify_deposit.rs

@@ -15,7 +15,7 @@ fn error(reason: DepositInvalid) -> BlockOperationError<DepositInvalid> {
 ///
 /// Spec v0.12.1
 pub fn verify_deposit_signature(deposit_data: &DepositData, spec: &ChainSpec) -> Result<()> {
-    let (public_key, signature, msg) = deposit_pubkey_signature_message(&deposit_data, spec)
+    let (public_key, signature, msg) = deposit_pubkey_signature_message(deposit_data, spec)
         .ok_or_else(|| error(DepositInvalid::BadBlsBytes))?;
 
     verify!(