[media] media_entity: get rid of a unused var

> > > +		if (rlink != link->reverse) {
> > > +			r++;
> >
> > The variable is incremented here but otherwise never used, you can remove it.

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