media: cx23885: remove redundant assignment to err

The variable err is assigned with a value that is never read and
it is re-assigned a new value later on.  The assignment is redundant
and can be removed.

Addresses-Coverity: ("Unused value")

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>