dmaengine: virt-dma: Convert to use list_for_each_entry_safe()

Use list_for_each_entry_safe() instead of open coding variants.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

drivers/dma/virt-dma.c

@@ -86,7 +86,7 @@ EXPORT_SYMBOL_GPL(vchan_find_desc);
 static void vchan_complete(unsigned long arg)
 {
 	struct virt_dma_chan *vc = (struct virt_dma_chan *)arg;
-	struct virt_dma_desc *vd;
+	struct virt_dma_desc *vd, *_vd;
 	struct dmaengine_desc_callback cb;
 	LIST_HEAD(head);
 
@@ -103,8 +103,7 @@ static void vchan_complete(unsigned long arg)
 
 	dmaengine_desc_callback_invoke(&cb, NULL);
 
-	while (!list_empty(&head)) {
-		vd = list_first_entry(&head, struct virt_dma_desc, node);
+	list_for_each_entry_safe(vd, _vd, &head, node) {
 		dmaengine_desc_get_callback(&vd->tx, &cb);
 
 		list_del(&vd->node);
@@ -119,9 +118,9 @@ static void vchan_complete(unsigned long arg)
 
 void vchan_dma_desc_free_list(struct virt_dma_chan *vc, struct list_head *head)
 {
-	while (!list_empty(head)) {
-		struct virt_dma_desc *vd = list_first_entry(head,
-			struct virt_dma_desc, node);
+	struct virt_dma_desc *vd, *_vd;
+
+	list_for_each_entry_safe(vd, _vd, head, node) {
 		if (dmaengine_desc_test_reuse(&vd->tx)) {
 			list_move_tail(&vd->node, &vc->desc_allocated);
 		} else {