V4L/DVB (7283): videobuf-dma-sg: Remove unused variable

Removed warning message:

 - videobuf-dma-sg.c: In function 'videobuf_dma_unmap':
 - videobuf-dma-sg.c:281: warning: unused variable 'dev'
Signed-off-by: Douglas Schilling Landgraf <dougsland@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/videobuf-dma-sg.c

@@ -273,8 +273,6 @@ int videobuf_dma_sync(struct videobuf_queue *q, struct videobuf_dmabuf *dma)
 
 int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 {
-	void                   *dev=q->dev;
-
 	MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
 	if (!dma->sglen)
 		return 0;