dmaengine: xgene-dma: convert callback to helper function

This is in preperation 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: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/xgene-dma.c

@@ -608,8 +608,7 @@ static void xgene_dma_run_tx_complete_actions(struct xgene_dma_chan *chan,
 	dma_cookie_complete(tx);
 
 	/* Run the link descriptor callback function */
-	if (tx->callback)
-		tx->callback(tx->callback_param);
+	dmaengine_desc_get_callback_invoke(tx, NULL);
 
 	dma_descriptor_unmap(tx);