pkt_sched: sch_hfsc: sch_htb: Add non-work-conserving warning handler.

Patrick McHardy <kaber@trash.net> suggested:
> How about making this flag and the warning message (in a out-of-line
> function) globally available? Other qdiscs (f.i. HFSC) can't deal with
> inner non-work-conserving qdiscs as well.

This patch uses qdisc->flags field of "suspected" child qdisc.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 4082f39..e37fe31 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -85,6 +85,7 @@
 		struct nlattr *tab);
 extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
 extern void qdisc_put_stab(struct qdisc_size_table *tab);
+extern void qdisc_warn_nonwc(char *txt, struct Qdisc *qdisc);
 
 extern void __qdisc_run(struct Qdisc *q);