dmaengine: sa11x0: use sg_nents_for_dma() helper

Instead of open coded variant let's use recently introduced helper.

Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20260108105619.3513561-12-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: andy-shev

drivers/dma/sa11x0-dma.c

@@ -526,7 +526,7 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_slave_sg(
 	struct sa11x0_dma_chan *c = to_sa11x0_dma_chan(chan);
 	struct sa11x0_dma_desc *txd;
 	struct scatterlist *sgent;
-	unsigned i, j = sglen;
+	unsigned int i, j;
 	size_t size = 0;
 
 	/* SA11x0 channels can only operate in their native direction */
@@ -542,17 +542,15 @@ static struct dma_async_tx_descriptor *sa11x0_dma_prep_slave_sg(
 
 	for_each_sg(sg, sgent, sglen, i) {
 		dma_addr_t addr = sg_dma_address(sgent);
-		unsigned int len = sg_dma_len(sgent);
 
-		if (len > DMA_MAX_SIZE)
-			j += DIV_ROUND_UP(len, DMA_MAX_SIZE & ~DMA_ALIGN) - 1;
 		if (addr & DMA_ALIGN) {
 			dev_dbg(chan->device->dev, "vchan %p: bad buffer alignment: %pad\n",
 				&c->vc, &addr);
 			return NULL;
 		}
 	}
 
+	j = sg_nents_for_dma(sg, sglen, DMA_MAX_SIZE & ~DMA_ALIGN);
 	txd = kzalloc(struct_size(txd, sg, j), GFP_ATOMIC);
 	if (!txd) {
 		dev_dbg(chan->device->dev, "vchan %p: kzalloc failed\n", &c->vc);