[media] dvb_usb_v2: call streaming_ctrl() before kill urbs

Logically it is better ask hardware to stop streaming before
killing urbs carrying stream. Earlier it was just opposite.
Now code runs:
* submit urbs
* start streaming
** streaming ongoing **
* stop streaming
* kill urbs
Signed-off-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NMauro Carvalho Chehab <mchehab@redhat.com>

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

@@ -265,7 +265,6 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed,
 	/* stop feeding if it is last pid */
 	if (adap->feed_count == 0) {
 		dev_dbg(&d->udev->dev, "%s: stop feeding\n", __func__);
-		usb_urb_killv2(&adap->stream);
 
 		if (d->props->streaming_ctrl) {
 			ret = d->props->streaming_ctrl(
@@ -274,9 +273,11 @@ static inline int dvb_usb_ctrl_feed(struct dvb_demux_feed *dvbdmxfeed,
 				dev_err(&d->udev->dev, "%s: streaming_ctrl() " \
 						"failed=%d\n", KBUILD_MODNAME,
 						ret);
+				usb_urb_killv2(&adap->stream);
 				goto err_mutex_unlock;
 			}
 		}
+		usb_urb_killv2(&adap->stream);
 		mutex_unlock(&adap->sync_mutex);
 	}