Disable NMI watchdog by default properly

This reverts commit 6ebf622b2577c50b1f496bd6a5e8739e55ae7b1c and
replaces it with one that actually works.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index 486f4c6..82d9d85 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -187,10 +187,7 @@
 {
 	if (nmi_watchdog != NMI_DEFAULT)
 		return;
-	if (nmi_known_cpu())
-		nmi_watchdog = NMI_LOCAL_APIC;
-	else
-		nmi_watchdog = NMI_IO_APIC;
+	nmi_watchdog = NMI_NONE;
 }
 
 static int endflag __initdata = 0;