media: cx18: Fix typo in comments

Remove the repeated word 'and' from comments

Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>