[PATCH] NOHZ: Produce debug output instead of a BUG()

The BUG_ON() in tick_nohz_stop_sched_tick() triggers on some boxen.
Remove the BUG_ON and print information about the pending softirq
to allow better debugging of the problem.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/time/tick-sched.c

@@ -165,7 +165,9 @@ void tick_nohz_stop_sched_tick(void)
 		goto end;
 
 	cpu = smp_processor_id();
-	BUG_ON(local_softirq_pending());
+	if (unlikely(local_softirq_pending()))
+		printk(KERN_ERR "NOHZ: local_softirq_pending %02x\n",
+		       local_softirq_pending());
 
 	now = ktime_get();
 	/*