V4L/DVB (13553): v4l: Use the video_is_registered function in device drivers

Fix all device drivers to use the video_is_registered function instead
of checking video_device::minor.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/omap24xxcam.c b/drivers/media/video/omap24xxcam.c
index e2f137b..34eb965 100644
--- a/drivers/media/video/omap24xxcam.c
+++ b/drivers/media/video/omap24xxcam.c
@@ -1696,7 +1696,7 @@
 	omap24xxcam_sensor_exit(cam);
 
 	if (cam->vfd) {
-		if (cam->vfd->minor == -1) {
+		if (!video_is_registered(cam->vfd)) {
 			/*
 			 * The device was never registered, so release the
 			 * video_device struct directly.