nmi_watchdog: Turn it off by default

It was nice to enable it by default for testing - but before we
push it upstream we want it to be off - so that people can
opt-in gradually.

Cc: Don Zickus <dzickus@redhat.com>
Cc: peterz@infradead.org
Cc: gorcunov@gmail.com
Cc: aris@redhat.com
LKML-Reference: <1266880143-24943-1-git-send-email-dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

lib/Kconfig.debug

@@ -173,7 +173,6 @@ config DETECT_SOFTLOCKUP
 config NMI_WATCHDOG
 	bool "Detect Hard Lockups with an NMI Watchdog"
 	depends on DEBUG_KERNEL && PERF_EVENTS && PERF_EVENTS_NMI
-	default y
 	help
 	  Say Y here to enable the kernel to use the NMI as a watchdog
 	  to detect hard lockups.  This is useful when a cpu hangs for no