dmaengine: mv_xor_v2: convert callback to helper function

This is in preparation of moving to a callback that provides results to the
callback for the transaction. The conversion will maintain current behavior
and the driver must convert to new callback mechanism at a later time in
order to receive results.
Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/mv_xor_v2.c

@@ -589,9 +589,8 @@ static void mv_xor_v2_tasklet(unsigned long data)
 			 */
 			dma_cookie_complete(&next_pending_sw_desc->async_tx);
 
-			if (next_pending_sw_desc->async_tx.callback)
-				next_pending_sw_desc->async_tx.callback(
-				next_pending_sw_desc->async_tx.callback_param);
+			dmaengine_desc_get_callback_invoke(
+					&next_pending_sw_desc->async_tx, NULL);
 
 			dma_descriptor_unmap(&next_pending_sw_desc->async_tx);
 		}