Remove module-level allows

Now that this codebase is more mature, remove allow directives so that
if we introduce issues, the compiler will tell us.

Bug: none
Test: compiles
Test: keystore2_test
Change-Id: If24b4ea40e0e2e1368e575e1e0bf6004bb318a42
diff --git a/keystore2/src/security_level.rs b/keystore2/src/security_level.rs
index f7bf1c6..c234ad3 100644
--- a/keystore2/src/security_level.rs
+++ b/keystore2/src/security_level.rs
@@ -12,8 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#![allow(unused_variables)]
-
 //! This crate implements the IKeystoreSecurityLevel interface.
 
 use crate::globals::get_keymint_device;
@@ -63,7 +61,6 @@
 pub struct KeystoreSecurityLevel {
     security_level: SecurityLevel,
     keymint: Asp,
-    #[allow(dead_code)]
     hw_info: KeyMintHardwareInfo,
     km_uuid: Uuid,
     operation_db: OperationDb,
@@ -411,7 +408,7 @@
         attest_key_descriptor: Option<&KeyDescriptor>,
         params: &[KeyParameter],
         flags: i32,
-        entropy: &[u8],
+        _entropy: &[u8],
     ) -> Result<KeyMetadata> {
         if key.domain != Domain::BLOB && key.alias.is_none() {
             return Err(error::Error::Km(ErrorCode::INVALID_ARGUMENT))
@@ -497,7 +494,7 @@
     fn import_key(
         &self,
         key: &KeyDescriptor,
-        attestation_key: Option<&KeyDescriptor>,
+        _attestation_key: Option<&KeyDescriptor>,
         params: &[KeyParameter],
         flags: i32,
         key_data: &[u8],