net_sched: Add accessor function for packet length for qdiscs

Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_nat.c b/net/sched/act_nat.c
index 0a3c833..7b39ed4 100644
--- a/net/sched/act_nat.c
+++ b/net/sched/act_nat.c
@@ -124,7 +124,7 @@
 	egress = p->flags & TCA_NAT_FLAG_EGRESS;
 	action = p->tcf_action;
 
-	p->tcf_bstats.bytes += skb->len;
+	p->tcf_bstats.bytes += qdisc_pkt_len(skb);
 	p->tcf_bstats.packets++;
 
 	spin_unlock(&p->tcf_lock);