media: uvcvideo: Exit early if there is not int_urb

If there is no int_urb there is no need to do a clean stop.

Also we avoid calling usb_kill_urb(NULL). It is properly handled by the
usb framework, but it is not polite.

Now that we are at it, fix the code style in uvc_status_start() for
consistency.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Link: https://lore.kernel.org/r/20240926-guenter-mini-v7-3-690441953d4a@chromium.org
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

drivers/media/usb/uvc/uvc_status.c

diff --git a/drivers/media/usb/uvc/uvc_status.c b/drivers/media/usb/uvc/uvc_status.c
index 9c5e5e7..06c86751 100644
--- a/drivers/media/usb/uvc/uvc_status.c
+++ b/drivers/media/usb/uvc/uvc_status.c
@@ -308,7 +308,7 @@ static int uvc_status_start(struct uvc_device *dev, gfp_t flags)
 {
 	lockdep_assert_held(&dev->status_lock);
 
-	if (dev->int_urb == NULL)
+	if (!dev->int_urb)
 		return 0;
 
 	return usb_submit_urb(dev->int_urb, flags);
@@ -320,6 +320,9 @@ static void uvc_status_stop(struct uvc_device *dev)
 
 	lockdep_assert_held(&dev->status_lock);
 
+	if (!dev->int_urb)
+		return;
+
 	/*
 	 * Prevent the asynchronous control handler from requeing the URB. The
 	 * barrier is needed so the flush_status change is visible to other