x86: Convert some devices to use DIE_NMIUNKNOWN

They are a handful of places in the code that register a die_notifier
as a catch all in case no claims the NMI.  Unfortunately, they trigger
on events like DIE_NMI and DIE_NMI_IPI, which depending on when they
registered may collide with other handlers that have the ability to
determine if the NMI is theirs or not.

The function unknown_nmi_error() makes one last effort to walk the
die_chain when no one else has claimed the NMI before spitting out
messages that the NMI is unknown.

This is a better spot for these devices to execute any code without
colliding with the other handlers.

The two drivers modified are only compiled on x86 arches I believe, so
they shouldn't be affected by other arches that may not have
DIE_NMIUNKNOWN defined.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Corey Minyard <minyard@acm.org>
Cc: openipmi-developer@lists.sourceforge.net
Cc: dann frazier <dannf@hp.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1294348732-15030-3-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

drivers/char/ipmi/ipmi_watchdog.c

@@ -1081,7 +1081,7 @@ ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
 {
 	struct die_args *args = data;
 
-	if (val != DIE_NMI)
+	if (val != DIE_NMIUNKNOWN)
 		return NOTIFY_OK;
 
 	/* Hack, if it's a memory or I/O error, ignore it. */