net: sched: sch: add extack for change qdisc ops

This patch adds extack support for change callback for qdisc ops
structtur 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_cbs.c b/net/sched/sch_cbs.c
index d77c632..8bf6e16 100644
--- a/net/sched/sch_cbs.c
+++ b/net/sched/sch_cbs.c
@@ -246,7 +246,8 @@ static int cbs_enable_offload(struct net_device *dev, struct cbs_sched_data *q,
 	return 0;
 }
 
-static int cbs_change(struct Qdisc *sch, struct nlattr *opt)
+static int cbs_change(struct Qdisc *sch, struct nlattr *opt,
+		      struct netlink_ext_ack *extack)
 {
 	struct cbs_sched_data *q = qdisc_priv(sch);
 	struct net_device *dev = qdisc_dev(sch);
@@ -307,7 +308,7 @@ static int cbs_init(struct Qdisc *sch, struct nlattr *opt,
 
 	qdisc_watchdog_init(&q->watchdog, sch);
 
-	return cbs_change(sch, opt);
+	return cbs_change(sch, opt, extack);
 }
 
 static void cbs_destroy(struct Qdisc *sch)