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>

net/sched/sch_gred.c

@@ -466,7 +466,8 @@ errout:
 	return err;
 }
 
-static int gred_init(struct Qdisc *sch, struct nlattr *opt)
+static int gred_init(struct Qdisc *sch, struct nlattr *opt,
+		     struct netlink_ext_ack *extack)
 {
 	struct nlattr *tb[TCA_GRED_MAX + 1];
 	int err;