swiotlb: use unmap_single instead of swiotlb_unmap_single in swiotlb_free_coherent

We don't need any check in swiotlb_unmap_single here. unmap_single is
appropriate.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

lib/swiotlb.c

@@ -513,7 +513,7 @@ swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
 		free_pages((unsigned long) vaddr, get_order(size));
 	else
 		/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
-		swiotlb_unmap_single (hwdev, dma_handle, size, DMA_TO_DEVICE);
+		unmap_single(hwdev, vaddr, size, DMA_TO_DEVICE);
 }
 
 static void