Revert "net/sched: act_api: move TCA_EXT_WARN_MSG to the correct hierarchy"

This reverts commit 923b2e30dc9cd05931da0f64e2e23d040865c035.

This is not a correct fix as TCA_EXT_WARN_MSG is not a hierarchy to
TCA_ACT_TAB. I didn't notice the TC actions use different enum when adding
TCA_EXT_WARN_MSG. To fix the difference I will add a new WARN enum in
TCA_ROOT_MAX as Jamal suggested.

Signed-off-by: Hangbin Liu <[e-mail]>
Acked-by: Jamal Hadi Salim <[e-mail]>
Signed-off-by: Jakub Kicinski <[e-mail]>

net/sched/act_api.c

···
 	if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
 		goto out_nlmsg_trim;
 
+	nla_nest_end(skb, nest);
+
 	if (extack && extack->_msg &&
 	    nla_put_string(skb, TCA_EXT_WARN_MSG, extack->_msg))
 		goto out_nlmsg_trim;
-
-	nla_nest_end(skb, nest);
 
 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;