manual update from upstream:

Applied Al's change 06a544971f
to new location of swiotlb.c

Signed-off-by: Tony Luck <tony.luck@intel.com>

lib/swiotlb.c

@@ -433,7 +433,7 @@ sync_single(struct device *hwdev, char *dma_addr, size_t size,
 
 void *
 swiotlb_alloc_coherent(struct device *hwdev, size_t size,
-		       dma_addr_t *dma_handle, int flags)
+		       dma_addr_t *dma_handle, gfp_t flags)
 {
 	unsigned long dev_addr;
 	void *ret;