net: sched: sch: add extack for init callback

This patch adds extack support for init callback to prepare per-qdisc
specific changes for extack.

Cc: David Ahern <dsahern@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Alexander Aring <aring@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index fa03807..41d9b7d 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1017,7 +1017,8 @@ static void htb_work_func(struct work_struct *work)
 	rcu_read_unlock();
 }
 
-static int htb_init(struct Qdisc *sch, struct nlattr *opt)
+static int htb_init(struct Qdisc *sch, struct nlattr *opt,
+		    struct netlink_ext_ack *extack)
 {
 	struct htb_sched *q = qdisc_priv(sch);
 	struct nlattr *tb[TCA_HTB_MAX + 1];