[media] firewire: Deletion of an unnecessary check before the function call "dvb_unregister_device"

The dvb_unregister_device() function tests whether its argument is NULL
and then returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/firewire/firedtv-ci.c

@@ -253,6 +253,5 @@ int fdtv_ca_register(struct firedtv *fdtv)
 
 void fdtv_ca_release(struct firedtv *fdtv)
 {
-	if (fdtv->cadev)
-		dvb_unregister_device(fdtv->cadev);
+	dvb_unregister_device(fdtv->cadev);
 }