[NET_SCHED]: Use nla_nest_start/nla_nest_end

Use nla_nest_start/nla_nest_end for dumping nested attributes.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 585f8a6..da0f6c0 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1565,18 +1565,18 @@
 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb)
 {
 	struct cbq_sched_data *q = qdisc_priv(sch);
-	unsigned char *b = skb_tail_pointer(skb);
-	struct nlattr *nla;
+	struct nlattr *nest;
 
-	nla = (struct nlattr*)b;
-	NLA_PUT(skb, TCA_OPTIONS, 0, NULL);
+	nest = nla_nest_start(skb, TCA_OPTIONS);
+	if (nest == NULL)
+		goto nla_put_failure;
 	if (cbq_dump_attr(skb, &q->link) < 0)
 		goto nla_put_failure;
-	nla->nla_len = skb_tail_pointer(skb) - b;
+	nla_nest_end(skb, nest);
 	return skb->len;
 
 nla_put_failure:
-	nlmsg_trim(skb, b);
+	nla_nest_cancel(skb, nest);
 	return -1;
 }
 
@@ -1594,8 +1594,7 @@
 	       struct sk_buff *skb, struct tcmsg *tcm)
 {
 	struct cbq_class *cl = (struct cbq_class*)arg;
-	unsigned char *b = skb_tail_pointer(skb);
-	struct nlattr *nla;
+	struct nlattr *nest;
 
 	if (cl->tparent)
 		tcm->tcm_parent = cl->tparent->classid;
@@ -1604,15 +1603,16 @@
 	tcm->tcm_handle = cl->classid;
 	tcm->tcm_info = cl->q->handle;
 
-	nla = (struct nlattr*)b;
-	NLA_PUT(skb, TCA_OPTIONS, 0, NULL);
+	nest = nla_nest_start(skb, TCA_OPTIONS);
+	if (nest == NULL)
+		goto nla_put_failure;
 	if (cbq_dump_attr(skb, cl) < 0)
 		goto nla_put_failure;
-	nla->nla_len = skb_tail_pointer(skb) - b;
+	nla_nest_end(skb, nest);
 	return skb->len;
 
 nla_put_failure:
-	nlmsg_trim(skb, b);
+	nla_nest_cancel(skb, nest);
 	return -1;
 }