[SK_BUFF]: Introduce skb_reset_transport_header(skb)

For the common, open coded 'skb->h.raw = skb->data' operation, so that we can
later turn skb->h.raw into a offset, reducing the size of struct sk_buff in
64bit land while possibly keeping it as a pointer on 32bit.

This one touches just the most simple cases:

skb->h.raw = skb->data;
skb->h.raw = {skb_push|[__]skb_pull}()

The next ones will handle the slightly more "complex" cases.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipx/af_ipx.c b/net/ipx/af_ipx.c
index 9aa7b96..392f8bc 100644
--- a/net/ipx/af_ipx.c
+++ b/net/ipx/af_ipx.c
@@ -577,7 +577,7 @@
 	if (skb2) {
 		skb_reserve(skb2, out_offset);
 		skb_reset_network_header(skb2);
-		skb2->h.raw = skb2->data;
+		skb_reset_transport_header(skb2);
 		skb_put(skb2, skb->len);
 		memcpy(ipx_hdr(skb2), ipx_hdr(skb), skb->len);
 		memcpy(skb2->cb, skb->cb, sizeof(skb->cb));