[media] cx231xxx: fix typo in saddr_len check

The original code compared "saddr_len" with zero twice in a nonsensical
way.  I asked the list, and Andy Walls and Sri Deevi say that the second
check should be if "saddr_len == 1".

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Srinivasa Deevi <Srinivasa.deevi@conexant.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>