[PATCH] ipmi: use refcount in message handler

This patch is rather large, but it really can't be done in smaller chunks
easily and I believe it is an important change.  This has been out and tested
for a while in the latest IPMI driver release.  There are no functional
changes, just changes as necessary to convert the locking over (and a few
minor style updates).

The IPMI driver uses read/write locks to ensure that things exist while they
are in use.  This is bad from a number of points of view.  This patch removes
the rwlocks and uses refcounts and RCU lists to manage what the locks did.

Signed-off-by: Corey Minyard <minyard@acm.org>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>