[SG] Update drivers to use sg helpers

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 72ee4c9..46cae5a 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -625,7 +625,7 @@
 	scsi_for_each_sg(scp, sg, scp->use_sg, k) {
 		if (active) {
 			kaddr = (unsigned char *)
-				kmap_atomic(sg->page, KM_USER0);
+				kmap_atomic(sg_page(sg), KM_USER0);
 			if (NULL == kaddr)
 				return (DID_ERROR << 16);
 			kaddr_off = (unsigned char *)kaddr + sg->offset;
@@ -672,7 +672,7 @@
 	sg = scsi_sglist(scp);
 	req_len = fin = 0;
 	for (k = 0; k < scp->use_sg; ++k, sg = sg_next(sg)) {
-		kaddr = (unsigned char *)kmap_atomic(sg->page, KM_USER0);
+		kaddr = (unsigned char *)kmap_atomic(sg_page(sg), KM_USER0);
 		if (NULL == kaddr)
 			return -1;
 		kaddr_off = (unsigned char *)kaddr + sg->offset;