Currently the return error code is in ret is being assigned but not
used. It and should be returned by the return statement and currently
just 0 is being returned. Fix this.

Addresses-Coverity: ("Unused value")

Fixes: b9ad52aa ("media: rcar-vin: Rework parallel firmware parsing")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>