Fix warnings in preparation for Rust 1.54.0

This CL fixes several new warnings generated by rustc 1.54.0.

Bug: 194812675
Test: m rust
Change-Id: I3076313ea51c6f4e74029ad9fb45d6f0b6dea460
diff --git a/keystore2/src/attestation_key_utils.rs b/keystore2/src/attestation_key_utils.rs
index ca00539..b6a8e31 100644
--- a/keystore2/src/attestation_key_utils.rs
+++ b/keystore2/src/attestation_key_utils.rs
@@ -60,7 +60,7 @@
     let challenge_present = params.iter().any(|kp| kp.tag == Tag::ATTESTATION_CHALLENGE);
     match attest_key_descriptor {
         None if challenge_present => rem_prov_state
-            .get_remotely_provisioned_attestation_key_and_certs(&key, caller_uid, params, db)
+            .get_remotely_provisioned_attestation_key_and_certs(key, caller_uid, params, db)
             .context(concat!(
                 "In get_attest_key_and_cert_chain: ",
                 "Trying to get remotely provisioned attestation key."
@@ -71,7 +71,7 @@
                 })
             }),
         None => Ok(None),
-        Some(attest_key) => get_user_generated_attestation_key(&attest_key, caller_uid, db)
+        Some(attest_key) => get_user_generated_attestation_key(attest_key, caller_uid, db)
             .context("In get_attest_key_and_cert_chain: Trying to load attest key")
             .map(Some),
     }
@@ -83,7 +83,7 @@
     db: &mut KeystoreDB,
 ) -> Result<AttestationKeyInfo> {
     let (key_id_guard, blob, cert, blob_metadata) =
-        load_attest_key_blob_and_cert(&key, caller_uid, db)
+        load_attest_key_blob_and_cert(key, caller_uid, db)
             .context("In get_user_generated_attestation_key: Failed to load blob and cert")?;
 
     let issuer_subject: Vec<u8> = parse_subject_from_certificate(&cert).context(
@@ -105,7 +105,7 @@
         _ => {
             let (key_id_guard, mut key_entry) = db
                 .load_key_entry(
-                    &key,
+                    key,
                     KeyType::Client,
                     KeyEntryLoadBits::BOTH,
                     caller_uid,