1.57.0 lints (#2850)

## Issue Addressed

New rust lints

## Proposed Changes

- Boxing some enum variants
- removing some unused fields (is the validator lockfile unused? seemed so to me)

## Additional Info

- some error fields were marked as dead code but are logged out in areas
- left some dead fields in our ef test code because I assume they are useful for debugging?

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

common/eth2/src/types.rs

@@ -777,7 +777,7 @@ pub struct SseLateHead {
 #[derive(PartialEq, Debug, Serialize, Clone)]
 #[serde(bound = "T: EthSpec", untagged)]
 pub enum EventKind<T: EthSpec> {
-    Attestation(Attestation<T>),
+    Attestation(Box<Attestation<T>>),
     Block(SseBlock),
     FinalizedCheckpoint(SseFinalizedCheckpoint),
     Head(SseHead),

common/lockfile/src/lib.rs

@@ -11,7 +11,7 @@ use std::path::{Path, PathBuf};
 /// outage) caused the lockfile not to be deleted.
 #[derive(Debug)]
 pub struct Lockfile {
-    file: File,
+    _file: File,
     path: PathBuf,
     file_existed: bool,
 }
@@ -43,7 +43,7 @@ impl Lockfile {
             _ => LockfileError::IoError(path.clone(), e),
         })?;
         Ok(Self {
-            file,
+            _file: file,
             path,
             file_existed,
         })

common/logging/src/lib.rs

@@ -99,7 +99,7 @@ impl<'a> AlignedRecordDecorator<'a> {
 
 impl<'a> Write for AlignedRecordDecorator<'a> {
     fn write(&mut self, buf: &[u8]) -> Result<usize> {
-        if buf.iter().any(|c| is_ascii_control(c)) {
+        if buf.iter().any(u8::is_ascii_control) {
             let filtered = buf
                 .iter()
                 .cloned()

common/monitoring_api/src/lib.rs

@@ -128,7 +128,7 @@ impl MonitoringHttpClient {
             Error::BeaconMetricsFailed("Beacon metrics require db path".to_string())
         })?;
 
-        let freezer_db_path = self.db_path.as_ref().ok_or_else(|| {
+        let freezer_db_path = self.freezer_db_path.as_ref().ok_or_else(|| {
             Error::BeaconMetricsFailed("Beacon metrics require freezer db path".to_string())
         })?;
         let metrics =

common/validator_dir/src/validator_dir.rs

@@ -63,7 +63,7 @@ pub struct Eth1DepositData {
 pub struct ValidatorDir {
     dir: PathBuf,
     #[derivative(PartialEq = "ignore")]
-    lockfile: Lockfile,
+    _lockfile: Lockfile,
 }
 
 impl ValidatorDir {
@@ -85,7 +85,10 @@ impl ValidatorDir {
         let lockfile_path = dir.join(format!("{}.lock", VOTING_KEYSTORE_FILE));
         let lockfile = Lockfile::new(lockfile_path).map_err(Error::LockfileError)?;
 
-        Ok(Self { dir, lockfile })
+        Ok(Self {
+            dir,
+            _lockfile: lockfile,
+        })
     }
 
     /// Returns the `dir` provided to `Self::open`.