sched_4bsd: remove unused function sched_pctcpu_delta()

It is not used since c72188d85a.

Noted by:	jrtc27
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D54831

sys/kern/sched_4bsd.c

@@ -1639,40 +1639,6 @@ sched_pctcpu(struct thread *td)
 	return (ts->ts_pctcpu);
 }
 
-#ifdef RACCT
-/*
- * Calculates the contribution to the thread cpu usage for the latest
- * (unfinished) second.
- */
-fixpt_t
-sched_pctcpu_delta(struct thread *td)
-{
-	struct td_sched *ts;
-	fixpt_t delta;
-	int realstathz;
-
-	THREAD_LOCK_ASSERT(td, MA_OWNED);
-	ts = td_get_sched(td);
-	delta = 0;
-	realstathz = stathz ? stathz : hz;
-	if (ts->ts_cpticks != 0) {
-#if	(FSHIFT >= CCPU_SHIFT)
-		delta = (realstathz == 100)
-		    ? ((fixpt_t) ts->ts_cpticks) <<
-		    (FSHIFT - CCPU_SHIFT) :
-		    100 * (((fixpt_t) ts->ts_cpticks)
-		    << (FSHIFT - CCPU_SHIFT)) / realstathz;
-#else
-		delta = ((FSCALE - ccpu) *
-		    (ts->ts_cpticks *
-		    FSCALE / realstathz)) >> FSHIFT;
-#endif
-	}
-
-	return (delta);
-}
-#endif
-
 u_int
 sched_estcpu(struct thread *td)
 {

sys/sys/sched.h

@@ -114,11 +114,6 @@ void	sched_throw(struct thread *td);
 void	sched_unlend_prio(struct thread *td, u_char prio);
 void	sched_user_prio(struct thread *td, u_char prio);
 void	sched_userret_slowpath(struct thread *td);
-#ifdef	RACCT
-#ifdef	SCHED_4BSD
-fixpt_t	sched_pctcpu_delta(struct thread *td);
-#endif
-#endif
 
 static inline void
 sched_userret(struct thread *td)