net: sched: sch: add extack to change class

This patch adds extack support for class change callback api. This prepares
to handle extack support inside each specific class implementation.

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>

net/sched/sch_atm.c

@@ -191,7 +191,8 @@ static const struct nla_policy atm_policy[TCA_ATM_MAX + 1] = {
 };
 
 static int atm_tc_change(struct Qdisc *sch, u32 classid, u32 parent,
-			 struct nlattr **tca, unsigned long *arg)
+			 struct nlattr **tca, unsigned long *arg,
+			 struct netlink_ext_ack *extack)
 {
 	struct atm_qdisc_data *p = qdisc_priv(sch);
 	struct atm_flow_data *flow = (struct atm_flow_data *)*arg;