net: Use skb_frag_off accessors

Use accessor functions for skb fragment's page_offset instead
of direct references, in preparation for bvec conversion.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/hsi/clients/ssi_protocol.c

@@ -182,7 +182,7 @@ static void ssip_skb_to_msg(struct sk_buff *skb, struct hsi_msg *msg)
 		BUG_ON(!sg);
 		frag = &skb_shinfo(skb)->frags[i];
 		sg_set_page(sg, skb_frag_page(frag), skb_frag_size(frag),
-				frag->page_offset);
+				skb_frag_off(frag));
 	}
 }