clockevents: Make tick_device_lock static

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Ingo Molnar <mingo@elte.hu>

kernel/time/tick-common.c

@@ -34,7 +34,7 @@ DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
 ktime_t tick_next_period;
 ktime_t tick_period;
 int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
-DEFINE_SPINLOCK(tick_device_lock);
+static DEFINE_SPINLOCK(tick_device_lock);
 
 /*
  * Debugging: see timer_list.c

kernel/time/tick-internal.h

@@ -6,7 +6,6 @@
 #define TICK_DO_TIMER_BOOT	-2
 
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
-extern spinlock_t tick_device_lock;
 extern ktime_t tick_next_period;
 extern ktime_t tick_period;
 extern int tick_do_timer_cpu __read_mostly;