ARM/dma-mapping: don't set failed sg dma_address to DMA_MAPPING_ERROR

Setting the ->dma_address to DMA_MAPPING_ERROR is not part of the
->map_sg calling convention, so remove it.

Link: https://lore.kernel.org/linux-mips/20210716063241.GC13345@lst.de/Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>

arch/arm/mm/dma-mapping.c

@@ -1632,7 +1632,6 @@ static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 	for (i = 1; i < nents; i++) {
 		s = sg_next(s);
 
-		s->dma_address = DMA_MAPPING_ERROR;
 		s->dma_length = 0;
 
 		if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {