[media] af9033: continue polling unless critical IO error

That case is not IO error, so better to jump out now, but still
continue polling.

Cc: Bimow Chen <Bimow.Chen@ite.com.tw>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

drivers/media/dvb-frontends/af9033.c

@@ -1103,7 +1103,7 @@ static void af9033_stat_work(struct work_struct *work)
 			snr_val *= 2;
 			break;
 		default:
-			goto err;
+			goto err_schedule_delayed_work;
 		}
 
 		/* read current modulation */