[PATCH] IB: Optimize canceling a MAD

Optimize canceling a MAD.
- Eliminate searching timeout list in cancel case.
- Remove duplicate calls to queue work item.
- Eliminate resending a MAD before MAD is completed.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Hal Rosenstock <halr@voltaire.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>