net: sched: propagate extack to cls->destroy callbacks

Propagate extack to cls->destroy callbacks when called from
non-error paths.  On error paths pass NULL to avoid overwriting
the failure message.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 1b54fbf..762da5c 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -143,7 +143,8 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb,
 	return err;
 }
 
-static void cls_cgroup_destroy(struct tcf_proto *tp)
+static void cls_cgroup_destroy(struct tcf_proto *tp,
+			       struct netlink_ext_ack *extack)
 {
 	struct cls_cgroup_head *head = rtnl_dereference(tp->root);