Cleanup rpc (#10910)

* Remove unreachable error case

* Inline Ok

* Hoist Ok

core/src/rpc_service.rs

@@ -402,7 +402,6 @@ mod tests {
             rpc_service
                 .request_processor
                 .get_balance(&mint_keypair.pubkey(), None)
-                .unwrap()
                 .value
         );
         rpc_service.exit();