sunrpc: don't check for failure from mempool_alloc()

When mempool_alloc() is allowed to sleep (GFP_NOIO allows
sleeping) it cannot fail.
So rpc_alloc_task() cannot fail, so rpc_new_task doesn't need
to test for failure.
Consequently rpc_new_task() cannot fail, so the callers
don't need to test.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

net/sunrpc/clnt.c

@@ -1042,8 +1042,6 @@ struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 	struct rpc_task *task;
 
 	task = rpc_new_task(task_setup_data);
-	if (IS_ERR(task))
-		goto out;
 
 	rpc_task_set_client(task, task_setup_data->rpc_client);
 	rpc_task_set_rpc_message(task, task_setup_data->rpc_message);
@@ -1053,7 +1051,6 @@ struct rpc_task *rpc_run_task(const struct rpc_task_setup *task_setup_data)
 
 	atomic_inc(&task->tk_count);
 	rpc_execute(task);
-out:
 	return task;
 }
 EXPORT_SYMBOL_GPL(rpc_run_task);
@@ -1140,10 +1137,6 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
 	 * Create an rpc_task to send the data
 	 */
 	task = rpc_new_task(&task_setup_data);
-	if (IS_ERR(task)) {
-		xprt_free_bc_request(req);
-		goto out;
-	}
 	task->tk_rqstp = req;
 
 	/*
@@ -1158,7 +1151,6 @@ struct rpc_task *rpc_run_bc_task(struct rpc_rqst *req)
 	WARN_ON_ONCE(atomic_read(&task->tk_count) != 2);
 	rpc_execute(task);
 
-out:
 	dprintk("RPC: rpc_run_bc_task: task= %p\n", task);
 	return task;
 }

net/sunrpc/sched.c

@@ -965,11 +965,6 @@ struct rpc_task *rpc_new_task(const struct rpc_task_setup *setup_data)
 
 	if (task == NULL) {
 		task = rpc_alloc_task();
-		if (task == NULL) {
-			rpc_release_calldata(setup_data->callback_ops,
-					setup_data->callback_data);
-			return ERR_PTR(-ENOMEM);
-		}
 		flags = RPC_TASK_DYNAMIC;
 	}