Add various fixes to clippy lints

Thou shalt appease clippy

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -216,9 +216,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             .iter()
             .map(|root| match self.get_block(root)? {
                 Some(block) => Ok(block.body),
-                None => Err(Error::DBInconsistent(
-                    format!("Missing block: {}", root).into(),
-                )),
+                None => Err(Error::DBInconsistent(format!("Missing block: {}", root))),
             })
             .collect();
 

beacon_node/beacon_chain/src/iter.rs

@@ -57,7 +57,7 @@ impl<T: EthSpec, U: Store> Iterator for BlockRootsIterator<T, U> {
             return None;
         }
 
-        self.slot = self.slot - 1;
+        self.slot -= 1;
 
         match self.beacon_state.get_block_root(self.slot) {
             Ok(root) => Some(*root),
@@ -73,7 +73,7 @@ impl<T: EthSpec, U: Store> Iterator for BlockRootsIterator<T, U> {
 
                 self.beacon_state.get_block_root(self.slot).ok().cloned()
             }
-            _ => return None,
+            _ => None,
         }
     }
 }

beacon_node/eth2-libp2p/src/config.rs

@@ -57,12 +57,12 @@ impl Config {
 
     pub fn apply_cli_args(&mut self, args: &ArgMatches) -> Result<(), &'static str> {
         if let Some(listen_address_str) = args.value_of("listen-address") {
-            let listen_addresses = listen_address_str.split(",").map(Into::into).collect();
+            let listen_addresses = listen_address_str.split(',').map(Into::into).collect();
             self.listen_addresses = listen_addresses;
         }
 
         if let Some(boot_addresses_str) = args.value_of("boot-nodes") {
-            let boot_addresses = boot_addresses_str.split(",").map(Into::into).collect();
+            let boot_addresses = boot_addresses_str.split(',').map(Into::into).collect();
             self.boot_nodes = boot_addresses;
         }
 

beacon_node/eth2-libp2p/src/rpc/protocol.rs

@@ -42,7 +42,7 @@ impl RequestId {
     }
 
     /// Return the previous id.
-    pub fn previous(&self) -> Self {
+    pub fn previous(self) -> Self {
         Self(self.0 - 1)
     }
 }
@@ -220,7 +220,7 @@ impl Encode for RPCEvent {
             } => SszContainer {
                 is_request: true,
                 id: (*id).into(),
-                other: (*method_id).into(),
+                other: *method_id,
                 bytes: match body {
                     RPCRequest::Hello(body) => body.as_ssz_bytes(),
                     RPCRequest::Goodbye(body) => body.as_ssz_bytes(),
@@ -237,7 +237,7 @@ impl Encode for RPCEvent {
             } => SszContainer {
                 is_request: false,
                 id: (*id).into(),
-                other: (*method_id).into(),
+                other: *method_id,
                 bytes: match result {
                     RPCResponse::Hello(response) => response.as_ssz_bytes(),
                     RPCResponse::BeaconBlockRoots(response) => response.as_ssz_bytes(),

beacon_node/network/src/message_handler.rs

@@ -155,7 +155,7 @@ impl<T: BeaconChainTypes + 'static> MessageHandler<T> {
         if self
             .network_context
             .outstanding_outgoing_request_ids
-            .remove(&(peer_id.clone(), id.clone()))
+            .remove(&(peer_id.clone(), id))
             .is_none()
         {
             warn!(
@@ -250,7 +250,7 @@ impl NetworkContext {
         let id = self.generate_request_id(&peer_id);
 
         self.outstanding_outgoing_request_ids
-            .insert((peer_id.clone(), id.clone()), Instant::now());
+            .insert((peer_id.clone(), id), Instant::now());
 
         self.send_rpc_event(
             peer_id,