media: Fix media device minor registration

media: Fix media device minor registration

commit 8c89ddd536bbe97c1e50424778a139abbf5763c3 upstream.

The find_next_zero_bit() is called with the from and to arguments in the
wrong order. This results in the function always returning 0, and all
media devices being registered with minor 0. Furthermore, mdev->minor is
then used before being assigned with the find_next_zero_bit() return
value. This really makes sure we'll always use minor 0.

Fix this and let the system support more than one media device.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>