media: cec-pin: use IS_ERR instead of PTR_ERR_OR_ZERO
cec_allocate_adapter never returns NULL, so just use IS_ERR instead of
PTR_ERR_OR_ZERO.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>