vhost: Remove unnecessary variable

It is unnecessary to use ret variable to return the error
code, just return the error code directly.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/vhost.c

@@ -203,7 +203,6 @@ EXPORT_SYMBOL_GPL(vhost_poll_init);
 int vhost_poll_start(struct vhost_poll *poll, struct file *file)
 {
 	__poll_t mask;
-	int ret = 0;
 
 	if (poll->wqh)
 		return 0;
@@ -213,10 +212,10 @@ int vhost_poll_start(struct vhost_poll *poll, struct file *file)
 		vhost_poll_wakeup(&poll->wait, 0, 0, poll_to_key(mask));
 	if (mask & EPOLLERR) {
 		vhost_poll_stop(poll);
-		ret = -EINVAL;
+		return -EINVAL;
 	}
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(vhost_poll_start);