V4L/DVB: videobuf: add queue argument to videobuf_waiton()

videobuf_waiton() must unlock and relock ext_lock if it has to wait.
For that to happen it needs the videobuf_queue pointer.

Don't attempt to unlock/relock q->ext_lock unless it was locked in the
first place.

vb->state has to be protected by a spinlock to be safe.

This patch is based on code from Mauro Carvalho Chehab <mchehab@redhat.com>.

[mchehab@redhat.com: add extra argument to a few missing places]
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/saa7134/saa7134-core.c b/drivers/media/video/saa7134/saa7134-core.c
index 40bc635..c424c45 100644
--- a/drivers/media/video/saa7134/saa7134-core.c
+++ b/drivers/media/video/saa7134/saa7134-core.c
@@ -255,7 +255,7 @@
 	struct videobuf_dmabuf *dma=videobuf_to_dma(&buf->vb);
 	BUG_ON(in_interrupt());
 
-	videobuf_waiton(&buf->vb,0,0);
+	videobuf_waiton(q, &buf->vb, 0, 0);
 	videobuf_dma_unmap(q->dev, dma);
 	videobuf_dma_free(dma);
 	buf->vb.state = VIDEOBUF_NEEDS_INIT;