cls_matchall: fix tcf_unbind_filter missing

Fix tcf_unbind_filter missing in cls_matchall as this will trigger
WARN_ON() in cbq_destroy_class().

Fixes: fd62d9f5c5 ("net/sched: matchall: Fix configuration race")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_matchall.c

@@ -113,6 +113,8 @@ static void mall_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 	if (!head)
 		return;
 
+	tcf_unbind_filter(tp, &head->res);
+
 	if (!tc_skip_hw(head->flags))
 		mall_destroy_hw_filter(tp, head, (unsigned long) head, extack);