V4L/DVB (12903): DiB8000: fix channel search parameter initialization

This patch is fixing the initialization of the channel search parameters.

Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <pboettcher@dibcom.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>