[media] media: use unsigned for pad index

The pad index is unsigned. Replace the occurences of it where
pertinent.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/platform/omap3isp/isppreview.c

@@ -2144,7 +2144,7 @@ static int preview_link_setup(struct media_entity *entity,
 {
 	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
 	struct isp_prev_device *prev = v4l2_get_subdevdata(sd);
-	int index = local->index;
+	unsigned int index = local->index;
 
 	/* FIXME: this is actually a hack! */
 	if (is_media_entity_v4l2_subdev(remote->entity))