V4L/DVB (9480): Fix frontend DVBFE_ALGO_CUSTOM Search

Issue: Currently, the DVBFE_ALGO_CUSTOM is called only at the first tuning.
After the first call, the status is never set to force a new tuning.

Signed-off-by: Marco Schluessler <marco@lordzodiac.de>
Signed-off-by: Manu Abraham <manu@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>