lockup_detector: Remove unused panic_notifier

The panic notifer in lockup_detector just set did_panic to 1.
But did_panic is not used anywhere so we can just remove it.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: peterz@infradead.org
Cc: gorcunov@gmail.com
Cc: fweisbec@gmail.com
LKML-Reference: <1283310009-22168-4-git-send-email-dzickus@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

kernel/watchdog.c

@@ -43,7 +43,6 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
 static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
 #endif
 
-static int __read_mostly did_panic;
 static int __initdata no_watchdog;
 
 
@@ -180,18 +179,6 @@ static int is_softlockup(unsigned long touch_ts)
 	return 0;
 }
 
-static int
-watchdog_panic(struct notifier_block *this, unsigned long event, void *ptr)
-{
-	did_panic = 1;
-
-	return NOTIFY_DONE;
-}
-
-static struct notifier_block panic_block = {
-	.notifier_call = watchdog_panic,
-};
-
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 static struct perf_event_attr wd_hw_attr = {
 	.type		= PERF_TYPE_HARDWARE,
@@ -564,8 +551,6 @@ static int __init spawn_watchdog_task(void)
 	cpu_callback(&cpu_nfb, CPU_ONLINE, cpu);
 	register_cpu_notifier(&cpu_nfb);
 
-	atomic_notifier_chain_register(&panic_notifier_list, &panic_block);
-
 	return 0;
 }
 early_initcall(spawn_watchdog_task);