net_sched: Add qdisc __NET_XMIT_BYPASS flag

Patrick McHardy <kaber@trash.net> noticed that it would be nice to
handle NET_XMIT_BYPASS by NET_XMIT_SUCCESS with an internal qdisc flag
__NET_XMIT_BYPASS and to remove the mapping from dev_queue_xmit().

David Miller <davem@davemloft.net> spotted a serious bug in the first
version of this patch.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 538d79b..be35422 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -214,7 +214,7 @@
 	if ((cl = htb_find(skb->priority, sch)) != NULL && cl->level == 0)
 		return cl;
 
-	*qerr = NET_XMIT_BYPASS;
+	*qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
 	tcf = q->filter_list;
 	while (tcf && (result = tc_classify(skb, tcf, &res)) >= 0) {
 #ifdef CONFIG_NET_CLS_ACT
@@ -567,7 +567,7 @@
 		}
 #ifdef CONFIG_NET_CLS_ACT
 	} else if (!cl) {
-		if (ret == NET_XMIT_BYPASS)
+		if (ret & __NET_XMIT_BYPASS)
 			sch->qstats.drops++;
 		kfree_skb(skb);
 		return ret;
@@ -612,7 +612,7 @@
 		}
 #ifdef CONFIG_NET_CLS_ACT
 	} else if (!cl) {
-		if (ret == NET_XMIT_BYPASS)
+		if (ret & __NET_XMIT_BYPASS)
 			sch->qstats.drops++;
 		kfree_skb(skb);
 		return ret;