[media] dvb-core/en50221: use dvb_remove_device()

Commit da677fe14364 ("[media] dvb-core/en50221: use kref to manage
struct dvb_ca_private") moved the dvb_unregister_device() call to the
kref callback, but that left lots of stale device state visible to
userspace (e.g. in sysfs). By using dvb_remove_device() and
dvb_free_device() instead of dvb_unregister_device(), we can avoid
that.

Signed-off-by: Max Kellermann <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/dvb-core/dvb_ca_en50221.c

···
 {
 	unsigned int i;
 
-	dvb_unregister_device(ca->dvbdev);
+	dvb_free_device(ca->dvbdev);
 	for (i = 0; i < ca->slot_count; i++)
 		vfree(ca->slot_info[i].rx_buffer.data);
 
···
 	for (i = 0; i < ca->slot_count; i++) {
 		dvb_ca_en50221_slot_shutdown(ca, i);
 	}
+	dvb_remove_device(ca->dvbdev);
 	dvb_ca_private_put(ca);
 	pubca->private = NULL;
 }