dmaengine: dma-jz4780: Use dma_set_residue()

This is the standard method provided by dmaengine header.
Signed-off-by: Daniel Silsby <dansilsby@gmail.com>
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Tested-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dma-jz4780.c

@@ -639,6 +639,7 @@ static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
 	struct virt_dma_desc *vdesc;
 	enum dma_status status;
 	unsigned long flags;
+	unsigned long residue = 0;
 
 	status = dma_cookie_status(chan, cookie, txstate);
 	if ((status == DMA_COMPLETE) || (txstate == NULL))
@@ -649,13 +650,13 @@ static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,
 	vdesc = vchan_find_desc(&jzchan->vchan, cookie);
 	if (vdesc) {
 		/* On the issued list, so hasn't been processed yet */
-		txstate->residue = jz4780_dma_desc_residue(jzchan,
+		residue = jz4780_dma_desc_residue(jzchan,
 					to_jz4780_dma_desc(vdesc), 0);
 	} else if (cookie == jzchan->desc->vdesc.tx.cookie) {
-		txstate->residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
+		residue = jz4780_dma_desc_residue(jzchan, jzchan->desc,
 					jzchan->curr_hwdesc + 1);
-	} else
-		txstate->residue = 0;
+	}
+	dma_set_residue(txstate, residue);
 
 	if (vdesc && jzchan->desc && vdesc == &jzchan->desc->vdesc
 	    && jzchan->desc->status & (JZ_DMA_DCS_AR | JZ_DMA_DCS_HLT))