virtio: Use the sg_phys convenience function.

Simple cleanup.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 drivers/virtio/virtio_ring.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff -r 5aaf1429009a drivers/virtio/virtio_ring.c
--- a/drivers/virtio/virtio_ring.c	Tue Jan 15 21:55:44 2008 +1100
+++ b/drivers/virtio/virtio_ring.c	Tue Jan 15 22:05:23 2008 +1100
@@ -101,16 +101,14 @@ static int vring_add_buf(struct virtqueu
 	head = vq->free_head;
 	for (i = vq->free_head; out; i = vq->vring.desc[i].next, out--) {
 		vq->vring.desc[i].flags = VRING_DESC_F_NEXT;
-		vq->vring.desc[i].addr = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
-			+ sg->offset;
+		vq->vring.desc[i].addr = sg_phys(sg);
 		vq->vring.desc[i].len = sg->length;
 		prev = i;
 		sg++;
 	}
 	for (; in; i = vq->vring.desc[i].next, in--) {
 		vq->vring.desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE;
-		vq->vring.desc[i].addr = (page_to_pfn(sg_page(sg))<<PAGE_SHIFT)
-			+ sg->offset;
+		vq->vring.desc[i].addr = sg_phys(sg);
 		vq->vring.desc[i].len = sg->length;
 		prev = i;
 		sg++;