ia64/sba_iommu: remove the mapping_error dma_map_ops method

Return DMA_MAPPING_ERROR instead of 0 on a dma mapping failure and let
the core dma-mapping code handle the rest.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/ia64/hp/common/sba_iommu.c

@@ -974,7 +974,7 @@ static dma_addr_t sba_map_page(struct device *dev, struct page *page,
 
 	pide = sba_alloc_range(ioc, dev, size);
 	if (pide < 0)
-		return 0;
+		return DMA_MAPPING_ERROR;
 
 	iovp = (dma_addr_t) pide << iovp_shift;
 
@@ -2155,11 +2155,6 @@ static int sba_dma_supported (struct device *dev, u64 mask)
 	return ((mask & 0xFFFFFFFFUL) == 0xFFFFFFFFUL);
 }
 
-static int sba_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
-	return 0;
-}
-
 __setup("nosbagart", nosbagart);
 
 static int __init
@@ -2193,7 +2188,6 @@ const struct dma_map_ops sba_dma_ops = {
 	.map_sg			= sba_map_sg_attrs,
 	.unmap_sg		= sba_unmap_sg_attrs,
 	.dma_supported		= sba_dma_supported,
-	.mapping_error		= sba_dma_mapping_error,
 };
 
 void sba_dma_init(void)