perfcounters, sched: remove __task_delta_exec()

This function was left orphan by the latest round of sw-counter
cleanups.

[ Impact: remove unused kernel function ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/linux/kernel_stat.h

@@ -85,7 +85,6 @@ static inline unsigned int kstat_irqs(unsigned int irq)
 /*
  * Lock/unlock the current runqueue - to extract task statistics:
  */
-extern unsigned long long __task_delta_exec(struct task_struct *tsk, int update);
 extern unsigned long long task_delta_exec(struct task_struct *);
 
 extern void account_user_time(struct task_struct *, cputime_t, cputime_t);

kernel/sched.c

@@ -4546,29 +4546,6 @@ DEFINE_PER_CPU(struct kernel_stat, kstat);
 
 EXPORT_PER_CPU_SYMBOL(kstat);
 
-/*
- * Return any ns on the sched_clock that have not yet been banked in
- * @p in case that task is currently running.
- */
-unsigned long long __task_delta_exec(struct task_struct *p, int update)
-{
-	s64 delta_exec;
-	struct rq *rq;
-
-	rq = task_rq(p);
-	WARN_ON_ONCE(!runqueue_is_locked());
-	WARN_ON_ONCE(!task_current(rq, p));
-
-	if (update)
-		update_rq_clock(rq);
-
-	delta_exec = rq->clock - p->se.exec_start;
-
-	WARN_ON_ONCE(delta_exec < 0);
-
-	return delta_exec;
-}
-
 /*
  * Return any ns on the sched_clock that have not yet been banked in
  * @p in case that task is currently running.