media: staging/media/av7110/av7110: Fix typo in string

Remove the repeated ',' from string

Signed-off-by: Li zeming <zeming@nfschina.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>