[media] staging: as102: Fix the dvb device registration error path

Release already acquired resources when error happens during
devices registration steps.
Use dev_err()  where struct device is available, instead of driver
specific err().

Cc: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Sylwester Nawrocki <snjw23@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>