Revert "nohz: Make tick_nohz_irq_exit() irq safe"

This reverts commit 351429b2e62b6545bb10c756686393f29ba268a1. The
extra local_irq_save() is not longer needed as the call site now
always calls with interrupts disabled.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>

kernel/time/tick-sched.c

@@ -565,19 +565,14 @@ void tick_nohz_idle_enter(void)
  */
 void tick_nohz_irq_exit(void)
 {
-	unsigned long flags;
 	struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
 
 	if (!ts->inidle)
 		return;
 
-	local_irq_save(flags);
-
-	/* Cancel the timer because CPU already waken up from the C-states */
+	/* Cancel the timer because CPU already waken up from the C-states*/
 	menu_hrtimer_cancel();
 	__tick_nohz_idle_enter(ts);
-
-	local_irq_restore(flags);
 }
 
 /**