[media] dvb-usb: handle errors from dvb_net_init

From an audit of dvb_net_init callers, now that that function
returns -errno on error.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
1 file changed