Fix clippy (#793)

Author: justsmth

aws-lc-rs/src/aead/quic.rs

@@ -160,10 +160,8 @@ fn cipher_new_mask(
                 .try_into()
                 .map_err(|_| error::Unspecified)?;
             let input = block::Block::zero();
-            unsafe {
-                let counter = core::mem::transmute::<[u8; 4], u32>(*counter_bytes).to_le();
-                encrypt_block_chacha20(raw_key, input, nonce, counter)?
-            }
+            let counter = u32::from_ne_bytes(*counter_bytes).to_le();
+            encrypt_block_chacha20(raw_key, input, nonce, counter)?
         }
     };