Use rxrpc_is_service_call() rather than rxrpc_conn_is_service() if the call
is available just in case call->conn is NULL.
Signed-off-by: David Howells <dhowells@redhat.com>
        case RXRPC_PACKET_TYPE_BUSY:
                _proto("Rx BUSY %%%u", sp->hdr.serial);
 
-               if (rxrpc_conn_is_service(call->conn))
+               if (rxrpc_is_service_call(call))
                        goto protocol_error;
 
                write_lock_bh(&call->state_lock);
                default:
                        goto dead_call;
                case RXRPC_CALL_SUCCEEDED:
-                       if (rxrpc_conn_is_service(call->conn))
+                       if (rxrpc_is_service_call(call))
                                goto dead_call;
                        goto resend_final_ack;
                }