[media] si2165: Fix possible leak in si2165_upload_firmware()

In case of an error function si2165_upload_firmware() releases the already
requested firmware in the exit path. However, there is one deviation where
the function directly returns. Use the correct cleanup so that the firmware
memory gets freed correctly. Detected by Coverity CID 1269120.

Signed-off-by: Christian Engelmayer <cengelma@gmx.at>
Signed-off-by: Matthias Schwarzott <zzam@gentoo.org>
Reviewed-by: Luis de Bethencourt <luis.bg@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>