[PATCH] ipmi: fix panic ipmb response

The "null message handler" in the IPMI driver is used in startup and panic
situations to handle messages.  It was only designed to work with messages
from the local management controller, but in some cases it was used to get
messages from remote managmenet controllers, and the system would then
panic.  This patch makes the "null message handler" in the IPMI driver more
general so it works with any kind of message.

Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>