Fix few rust linter issues

vm/rust/src/jsonrpc.rs

@@ -295,13 +295,13 @@ fn make_state_diff(
         if existing_class_hash == ClassHash::default() {
             #[rustfmt::skip]
             deployed_contracts.push(DeployedContract {
-                address: pair.0.0.key().clone(),
+                address: *pair.0.0.key(),
                 class_hash: pair.1.0,
             });
         } else {
             #[rustfmt::skip]
             replaced_classes.push(ReplacedClass {
-                contract_address: pair.0.0.key().clone(),
+                contract_address: *pair.0.0.key(),
                 class_hash: pair.1.0,
             });
         }
@@ -315,9 +315,9 @@ fn make_state_diff(
         deployed_contracts,
         #[rustfmt::skip]
         storage_diffs: diff.storage_updates.into_iter().map(| v | StorageDiff {
-            address: v.0.0.key().clone(),
+            address: *v.0.0.key(),
             storage_entries: v.1.into_iter().map(| e | Entry {
-                key: e.0.0.key().clone(),
+                key: *e.0.0.key(),
                 value: e.1
             }).collect()
         }).collect(),
@@ -329,7 +329,7 @@ fn make_state_diff(
         deprecated_declared_classes,
         #[rustfmt::skip]
         nonces: diff.address_to_nonce.into_iter().map(| v | Nonce {
-          contract_address: v.0.0.key().clone(),
+          contract_address: *v.0.0.key(),
           nonce: v.1.0,
         }).collect(),
         replaced_classes,

vm/rust/src/juno_state_reader.rs

@@ -149,10 +149,10 @@ pub fn contract_class_from_json_str(raw_json: &str) -> Result<ContractClass, Str
     let v0_class = ContractClassV0::try_from_json_string(raw_json);
     let v1_class = ContractClassV1::try_from_json_string(raw_json);
 
-    if v0_class.is_ok() {
-        Ok(v0_class.unwrap().into())
-    } else if v1_class.is_ok() {
-        Ok(v1_class.unwrap().into())
+    if let Ok(class) = v0_class {
+        Ok(class.into())
+    } else if let Ok(class) = v1_class {
+        Ok(class.into())
     } else {
         Err("not a valid contract class".to_string())
     }