[PATCH] ia64: fix bug in SN2 sn_pci_map_sg that causes MCA

If sg->dma_address is set, we try to do a __pa() on a dma_address,
then, later, create a dma_addresss from a munged dma_address.  When
this bogus dma_address is used by the card, it results in MCAs.

arch/ia64/sn/io/machvec/pci_dma.c

@@ -279,8 +279,7 @@ sn_pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg, int nents, int dire
 	 * scatterlist.
 	 */
 	for (i = 0; i < nents; i++, sg++) {
-		phys_addr = __pa(sg->dma_address ? sg->dma_address :
-			(unsigned long)page_address(sg->page) + sg->offset);
+		phys_addr = __pa((unsigned long)page_address(sg->page) + sg->offset);
 
 		/*
 		 * Handle the most common case: 64 bit cards.  This