SUNRPC: task should be exit if encode return EKEYEXPIRED more times

If the rpc.gssd always return cred success, but now the cred is
expired, then the task will loop in call_refresh and call_transmit.

Exit the rpc task after retry.
Signed-off-by: ZhangXiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/clnt.c

@@ -1814,7 +1814,14 @@ call_encode(struct rpc_task *task)
 			rpc_delay(task, HZ >> 4);
 			break;
 		case -EKEYEXPIRED:
+			if (!task->tk_cred_retry) {
+				rpc_exit(task, task->tk_status);
+			} else {
 				task->tk_action = call_refresh;
+				task->tk_cred_retry--;
+				dprintk("RPC: %5u %s: retry refresh creds\n",
+					task->tk_pid, __func__);
+			}
 			break;
 		default:
 			rpc_call_rpcerror(task, task->tk_status);