V4L/DVB (5545): Saa7146: Release capture buffers on device close

If the video device (saa7146 on a FF card) was open for capturing,
the close call didn't release the capture buffers.
Signed-off-by: NHartmut Birr <e9hack@gmail.com>
Signed-off-by: NOliver Endriss <o.endriss@gmx.de>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/common/saa7146_video.c

@@ -1428,6 +1428,7 @@ static void video_close(struct saa7146_dev *dev, struct file *file)
 {
 	struct saa7146_fh *fh = (struct saa7146_fh *)file->private_data;
 	struct saa7146_vv *vv = dev->vv_data;
+	struct videobuf_queue *q = &fh->video_q;
 	int err;
 
 	if (IS_CAPTURE_ACTIVE(fh) != 0) {
@@ -1436,6 +1437,11 @@ static void video_close(struct saa7146_dev *dev, struct file *file)
 		err = saa7146_stop_preview(fh);
 	}
 
+	// release all capture buffers
+	mutex_lock(&q->lock);
+	videobuf_read_stop(q);
+	mutex_unlock(&q->lock);
+
 	/* hmm, why is this function declared void? */
 	/* return err */
 }