staging: wilc1000: wilc_msgqueue: release semaphore in error path

It should be called up(&mq->sem) to release semaphore before returning
error codes as -EFAULT when list is empty.
Signed-off-by: Chaehyun Lim <chaehyun.lim@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wilc1000/wilc_msgqueue.c

@@ -126,6 +126,7 @@ int wilc_mq_recv(struct message_queue *mq,
 
 	if (list_empty(&mq->msg_list)) {
 		spin_unlock_irqrestore(&mq->lock, flags);
+		up(&mq->sem);
 		PRINT_ER("msg is null\n");
 		return -EFAULT;
 	}