fix clippy

Signed-off-by: Yang Zhang <yang.zhang@pingcap.com>

Author: v01dstar

src/engine.rs

@@ -1422,7 +1422,7 @@ pub(crate) mod tests {
         let empty_entry = Entry::new();
         assert_eq!(empty_entry.compute_size(), 0);
         log_batch
-            .add_entries::<Entry>(0, &[empty_entry.clone()])
+            .add_entries::<Entry>(0, std::slice::from_ref(&empty_entry))
             .unwrap();
         engine.write(&mut log_batch, false).unwrap();
         let empty_state = RaftLocalState::new();
@@ -1432,7 +1432,7 @@ pub(crate) mod tests {
             .unwrap();
         engine.write(&mut log_batch, false).unwrap();
         log_batch
-            .add_entries::<Entry>(2, &[empty_entry.clone()])
+            .add_entries::<Entry>(2, std::slice::from_ref(&empty_entry))
             .unwrap();
         log_batch
             .put_message(2, b"key".to_vec(), &empty_state)

src/log_batch.rs

@@ -1633,7 +1633,7 @@ mod tests {
     #[cfg(feature = "nightly")]
     #[bench]
     fn bench_log_batch_add_entry_and_encode(b: &mut test::Bencher) {
-        use rand::{Rng, random};
+        use rand::random;
         fn details(log_batch: &mut LogBatch, entries: &[Entry], regions: usize) {
             for _ in 0..regions {
                 log_batch.add_entries::<Entry>(random(), entries).unwrap();

src/swappy_allocator.rs

@@ -402,7 +402,7 @@ mod tests {
         }
         unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout) {
             self.dealloc.fetch_add(1, Ordering::Relaxed);
-            std::alloc::Global.deallocate(ptr, layout)
+            unsafe { std::alloc::Global.deallocate(ptr, layout) }
         }
         unsafe fn grow(
             &self,
@@ -414,7 +414,7 @@ mod tests {
             if self.err_mode.load(Ordering::Relaxed) {
                 Err(AllocError)
             } else {
-                std::alloc::Global.grow(ptr, old_layout, new_layout)
+                unsafe { std::alloc::Global.grow(ptr, old_layout, new_layout) }
             }
         }
         unsafe fn shrink(
@@ -427,7 +427,7 @@ mod tests {
             if self.err_mode.load(Ordering::Relaxed) {
                 Err(AllocError)
             } else {
-                std::alloc::Global.shrink(ptr, old_layout, new_layout)
+                unsafe { std::alloc::Global.shrink(ptr, old_layout, new_layout) }
             }
         }
     }

tests/benches/bench_recovery.rs

@@ -118,7 +118,7 @@ fn dir_size(path: &str) -> ReadableSize {
 
 fn bench_recovery(c: &mut Criterion) {
     // prepare input
-    let cfgs = vec![
+    let cfgs = [
         (
             "default".to_owned(),
             Config {