SUNRPC: Don't bother changing the sigmask for asynchronous RPC calls

The caller will never sleep in rpc_execute, so don't bother setting the
sigmask.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/clnt.c

@@ -579,9 +579,12 @@ struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 	}
 	atomic_inc(&task->tk_count);
 	/* Mask signals on synchronous RPC calls and RPCSEC_GSS upcalls */
+	if (!RPC_IS_ASYNC(task)) {
 		rpc_task_sigmask(task, &oldset);
 		rpc_execute(task);
 		rpc_restore_sigmask(&oldset);
+	} else
+		rpc_execute(task);
 	ret = task;
 out:
 	return ret;