dmaengine: bcm2835-dma: Fix memory leak when stopping a running transfer

The vd->node is removed from the lists when the transfer started so the
vchan_get_all_descriptors() will not find it. This results memory leak.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/bcm2835-dma.c b/drivers/dma/bcm2835-dma.c
index 0723096..c92d6a7 100644
--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -475,6 +475,7 @@
 	 * c->desc is NULL and exit.)
 	 */
 	if (c->desc) {
+		bcm2835_dma_desc_free(&c->desc->vd);
 		c->desc = NULL;
 		bcm2835_dma_abort(c->chan_base);