[media] ngene: fix compile warning

drivers/media/dvb/ngene/ngene-core.c: In function 'ngene_start':
drivers/media/dvb/ngene/ngene-core.c:1308:16: warning: unused variable 'flags'

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>