media: ngene: Add dvb_ca_en50221_init return value check

The return value of dvb_ca_en50221_init() is not checked here that may
cause undefined behavior in case of nonzero value return.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 25aee3de ("[media] Rename media/dvb as media/pci")
Signed-off-by: Aleksandr Burakov <a.burakov@rosalinux.ru>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>