[media] media: fix au0828_analog_register() to not free au0828_dev

au0828_analog_register() frees au0828_dev when it fails to
locate isoc endpoint. au0828_usb_probe() continues with dvb
and rc probe and registration assuming dev is still valid.
When au0828_analog_register() fails to locate isoc endpoint,
it should return without free'ing au0828_dev. Otherwise, the
probe will fail as dev is null when au0828_dvb_register() is
called.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>