[media] v4l: omap4iss: Remove duplicate video_is_registered() check

The video_unregister_device() function checks if the video device is
registered before proceeding, remote the duplicate check from the
driver.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/staging/media/omap4iss/iss_video.c

@@ -1119,6 +1119,5 @@ int omap4iss_video_register(struct iss_video *video, struct v4l2_device *vdev)
 
 void omap4iss_video_unregister(struct iss_video *video)
 {
-	if (video_is_registered(&video->video))
-		video_unregister_device(&video->video);
+	video_unregister_device(&video->video);
 }