[media] af9035: relax frontend callback error handling

It is not good idea to return error for missing callback
handler as whole callback as optional and could be missing
by intentionally.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
1 file changed