perf: Remove unused function perf_mux_hrtimer_cancel()

Reported-by: NIngo Molnar <mingo@kernel.org>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

kernel/events/core.c

@@ -772,34 +772,6 @@ static enum hrtimer_restart perf_mux_hrtimer_handler(struct hrtimer *hr)
 	return ret;
 }
 
-/* CPU is going down */
-static void perf_mux_hrtimer_cancel(int cpu)
-{
-	struct perf_cpu_context *cpuctx;
-	struct pmu *pmu;
-	unsigned long flags;
-
-	if (WARN_ON(cpu != smp_processor_id()))
-		return;
-
-	local_irq_save(flags);
-
-	rcu_read_lock();
-
-	list_for_each_entry_rcu(pmu, &pmus, entry) {
-		cpuctx = this_cpu_ptr(pmu->pmu_cpu_context);
-
-		if (pmu->task_ctx_nr == perf_sw_context)
-			continue;
-
-		hrtimer_cancel(&cpuctx->hrtimer);
-	}
-
-	rcu_read_unlock();
-
-	local_irq_restore(flags);
-}
-
 static void __perf_mux_hrtimer_init(struct perf_cpu_context *cpuctx, int cpu)
 {
 	struct hrtimer *timer = &cpuctx->hrtimer;