media: ivtv: update *pos correctly in ivtv_read_pos()

media: ivtv: update *pos correctly in ivtv_read_pos()

BugLink: https://bugs.launchpad.net/bugs/1863019
[ Upstream commit f8e579f3ca0973daef263f513da5edff520a6c0d ]

We had intended to update *pos, but the current code is a no-op.

Fixes: 1a0adaf37c30 ("V4L/DVB (5345): ivtv driver for Conexant cx23416/cx23415 MPEG encoder/decoder")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>