dmaengine: dma-jz4780: Simplify jz4780_dma_desc_residue()

Simple cleanup, no changes to actual logic here.
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

@@ -610,22 +610,17 @@ static size_t jz4780_dma_desc_residue(struct jz4780_dma_chan *jzchan,
 	struct jz4780_dma_desc *desc, unsigned int next_sg)
 {
 	struct jz4780_dma_dev *jzdma = jz4780_dma_chan_parent(jzchan);
-	unsigned int residue, count;
+	unsigned int count = 0;
 	unsigned int i;
 
-	residue = 0;
-
 	for (i = next_sg; i < desc->count; i++)
-		residue += (desc->desc[i].dtc & GENMASK(23, 0)) <<
-			jzchan->transfer_shift;
+		count += desc->desc[i].dtc & GENMASK(23, 0);
 
-	if (next_sg != 0) {
-		count = jz4780_dma_chn_readl(jzdma, jzchan->id,
+	if (next_sg != 0)
+		count += jz4780_dma_chn_readl(jzdma, jzchan->id,
 					 JZ_DMA_REG_DTC);
-		residue += count << jzchan->transfer_shift;
-	}
 
-	return residue;
+	return count << jzchan->transfer_shift;
 }
 
 static enum dma_status jz4780_dma_tx_status(struct dma_chan *chan,