[media] dvb_usb_v2: use dummy function defines instead stub functions

I think it is better (cheaper) to use dummy defines for functions
that has no meaning when remote controller is disabled by Kconfig.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/dvb-usb-v2/dvb_usb_core.c

@@ -204,15 +204,8 @@ static int dvb_usbv2_remote_exit(struct dvb_usb_device *d)
 	return 0;
 }
 #else
-static int dvb_usbv2_remote_init(struct dvb_usb_device *d)
-{
-	return 0;
-}
-
-static int dvb_usbv2_remote_exit(struct dvb_usb_device *d)
-{
-	return 0;
-}
+	#define dvb_usbv2_remote_init(args...) 0
+	#define dvb_usbv2_remote_exit(args...)
 #endif
 
 static void dvb_usb_data_complete(struct usb_data_stream *stream, u8 *buf,