x86: enable irq in default_idle on 64-bit

local_irq_enable() is missing after sched_clock_idle_wakeup_event().
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/process_64.c

@@ -126,8 +126,8 @@ static void default_idle(void)
 		t1 = ktime_get();
 		t1n = ktime_to_ns(t1);
 		sched_clock_idle_wakeup_event(t1n - t0n);
-	} else
-		local_irq_enable();
+	}
+	local_irq_enable();
 	current_thread_info()->status |= TS_POLLING;
 }