dmaengine: iop-adma: 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/iop-adma.c

@@ -71,8 +71,7 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
 		/* call the callback (must not sleep or submit new
 		 * operations to this channel)
 		 */
-		if (tx->callback)
-			tx->callback(tx->callback_param);
+		dmaengine_desc_get_callback_invoke(tx, NULL);
 
 		dma_descriptor_unmap(tx);
 		if (desc->group_head)