SUNRPC: If there is no reply expected, bail early from call_decode

mainline inclusion
from mainline-4.20-rc1
commit 9ee94d3e
category: bugfix
bugzilla: 51820
CVE: NA

-------------------------------------------------
Signed-off-by: NTrond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: NHuang Guobin <huangguobin4@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

net/sunrpc/clnt.c

@@ -2264,6 +2264,11 @@ call_decode(struct rpc_task *task)
 
 	dprint_status(task);
 
+	if (!decode) {
+		task->tk_action = rpc_exit_task;
+		return;
+	}
+
 	if (task->tk_flags & RPC_CALL_MAJORSEEN) {
 		if (clnt->cl_chatty) {
 			printk(KERN_NOTICE "%s: server %s OK\n",
@@ -2301,13 +2306,11 @@ call_decode(struct rpc_task *task)
 			goto out_retry;
 		return;
 	}
-
 	task->tk_action = rpc_exit_task;
 
-	if (decode) {
-		task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
-						      task->tk_msg.rpc_resp);
-	}
+	task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
+					      task->tk_msg.rpc_resp);
+
 	dprintk("RPC: %5u call_decode result %d\n", task->tk_pid,
 			task->tk_status);
 	return;