convert media_request_get_by_fd()

the only thing done after fdput() (in failure cases) is a printk; safely
transposable with fdput()...

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

drivers/media/mc/mc-request.c

@@ -246,22 +246,21 @@ static const struct file_operations request_fops = {
 struct media_request *
 media_request_get_by_fd(struct media_device *mdev, int request_fd)
 {
-	struct fd f;
 	struct media_request *req;
 
 	if (!mdev || !mdev->ops ||
 	    !mdev->ops->req_validate || !mdev->ops->req_queue)
 		return ERR_PTR(-EBADR);
 
-	f = fdget(request_fd);
-	if (!fd_file(f))
-		goto err_no_req_fd;
+	CLASS(fd, f)(request_fd);
+	if (fd_empty(f))
+		goto err;
 
 	if (fd_file(f)->f_op != &request_fops)
-		goto err_fput;
+		goto err;
 	req = fd_file(f)->private_data;
 	if (req->mdev != mdev)
-		goto err_fput;
+		goto err;
 
 	/*
 	 * Note: as long as someone has an open filehandle of the request,
@@ -272,14 +271,9 @@ media_request_get_by_fd(struct media_device *mdev, int request_fd)
 	 * before media_request_get() is called.
 	 */
 	media_request_get(req);
-	fdput(f);
-
 	return req;
 
-err_fput:
-	fdput(f);
-
-err_no_req_fd:
+err:
 	dev_dbg(mdev->dev, "cannot find request_fd %d\n", request_fd);
 	return ERR_PTR(-EINVAL);
 }