[media] gspca_main: wake wq on streamoff

We check for not streaming as a condition to abort waiting in dqbuf, so
when another thread does a streamoff we should wake the wq.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/gspca/gspca.c

@@ -1634,6 +1634,8 @@ static int vidioc_streamoff(struct file *file, void *priv,
 	gspca_dev->usb_err = 0;
 	gspca_stream_off(gspca_dev);
 	mutex_unlock(&gspca_dev->usb_lock);
+	/* In case another thread is waiting in dqbuf */
+	wake_up_interruptible(&gspca_dev->wq);
 
 	/* empty the transfer queues */
 	atomic_set(&gspca_dev->fr_q, 0);