pkt_sched: sch_htb: Fix deadlock in hrtimers triggered by HTB

pkt_sched: sch_htb: Fix deadlock in hrtimers triggered by HTB

[ Upstream commit: none

  This is a quick fix for -stable purposes.  Upstream fixes these
  problems via a large set of invasive hrtimer changes.  ]

Most probably there is a (still unproven) race in hrtimers (before
2.6.29 kernels), which causes a corruption of hrtimers rbtree. This
patch doesn't fix it, but should let HTB avoid triggering the bug.

Reported-by: Denys Fedoryschenko <denys@visp.net.lb>
Reported-by: Badalian Vyacheslav <slavon@bigtelecom.ru>
Reported-by: Chris Caputo <ccaputo@alt.net>
Tested-by: Badalian Vyacheslav <slavon@bigtelecom.ru>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>