net: Add and use skb_mark_not_on_list().
An SKB is not on a list if skb->next is NULL.
Codify this convention into a helper function and use it
where we are dequeueing an SKB and need to mark it as such.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index 6f74a42..a4530e8 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -162,7 +162,7 @@ static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
nb = 0;
while (segs) {
nskb = segs->next;
- segs->next = NULL;
+ skb_mark_not_on_list(segs);
qdisc_skb_cb(segs)->pkt_len = segs->len;
len += segs->len;
ret = qdisc_enqueue(segs, q->qdisc, to_free);
