media: uvcvideo: Remove unnecessary NULL check before debugfs_remove_recursive

debugfs_remove_recursive() accepts a NULL parameter and returns
immediately, there's no need for a NULL check in the caller.

This issue was detected with the help of Coccinelle.

[Reword commit message, address uvc_debugfs_cleanup_stream()]
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

drivers/media/usb/uvc/uvc_debugfs.c

@@ -106,9 +106,6 @@ void uvc_debugfs_init_stream(struct uvc_streaming *stream)
 
 void uvc_debugfs_cleanup_stream(struct uvc_streaming *stream)
 {
-	if (stream->debugfs_dir == NULL)
-		return;
-
 	debugfs_remove_recursive(stream->debugfs_dir);
 	stream->debugfs_dir = NULL;
 }
@@ -128,6 +125,5 @@ void uvc_debugfs_init(void)
 
 void uvc_debugfs_cleanup(void)
 {
-	if (uvc_debugfs_root_dir != NULL)
 	debugfs_remove_recursive(uvc_debugfs_root_dir);
 }