posix-cpu-timers: Use clock ID in posix_cpu_timer_set()

Extract the clock ID (PROF/VIRT/SCHED) from the clock selector and use it
as argument to the sample functions. That allows to simplify them once all
callers are fixed.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lkml.kernel.org/r/20190821192920.050770464@linutronix.de

kernel/time/posix-cpu-timers.c

@@ -556,10 +556,11 @@ static void cpu_timer_fire(struct k_itimer *timer)
 static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 			       struct itimerspec64 *new, struct itimerspec64 *old)
 {
-	unsigned long flags;
-	struct sighand_struct *sighand;
-	struct task_struct *p = timer->it.cpu.task;
+	clockid_t clkid = CPUCLOCK_WHICH(timer->it_clock);
 	u64 old_expires, new_expires, old_incr, val;
+	struct task_struct *p = timer->it.cpu.task;
+	struct sighand_struct *sighand;
+	unsigned long flags;
 	int ret;
 
 	if (WARN_ON_ONCE(!p))
@@ -606,9 +607,9 @@ static int posix_cpu_timer_set(struct k_itimer *timer, int timer_flags,
 	 * check if it's already passed.  In short, we need a sample.
 	 */
 	if (CPUCLOCK_PERTHREAD(timer->it_clock)) {
-		cpu_clock_sample(timer->it_clock, p, &val);
+		cpu_clock_sample(clkid, p, &val);
 	} else {
-		cpu_clock_sample_group(timer->it_clock, p, &val, true);
+		cpu_clock_sample_group(clkid, p, &val, true);
 	}
 
 	if (old) {