net: sched: unmark chain as explicitly created on delete

Once user manually deletes the chain using "chain del", the chain cannot
be marked as explicitly created anymore.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Fixes: 32a4f5ec ("net: sched: introduce chain object to uapi")
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_api.c

@@ -1844,6 +1844,7 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
 		 * to the chain previously taken during addition.
 		 */
 		tcf_chain_put_explicitly_created(chain);
+		chain->explicitly_created = false;
 		break;
 	case RTM_GETCHAIN:
 		err = tc_chain_notify(chain, skb, n->nlmsg_seq,