[media] tda10071: do not get_frontend() when not ready

This is a bit hack, but returning error when driver is not tuned yet
causes DVBv5 zap stop polling DVBv5 statistics. Thus return 0 even
callback is called during invalid device state.
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/tda10071.c

@@ -717,7 +717,7 @@ static int tda10071_get_frontend(struct dvb_frontend *fe)
 	u8 buf[5], tmp;
 
 	if (!dev->warm || !(dev->fe_status & FE_HAS_LOCK)) {
-		ret = -EFAULT;
+		ret = 0;
 		goto error;
 	}