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

drivers/media/dvb-frontends/tda10071.c

···
 	u8 buf[5], tmp;
 
 	if (!dev->warm || !(dev->fe_status & FE_HAS_LOCK)) {
-		ret = -EFAULT;
+		ret = 0;
 		goto error;
 	}