sched/core: Remove unused rq::last_load_update_tick

The following commit:

  5e83eafb ("sched/fair: Remove the rq->cpu_load[] update code")

eliminated the last use case for rq->last_load_update_tick, so remove
the field as well.
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Vincent Donnefort <vincent.donnefort@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/1584710495-308969-1-git-send-email-vincent.donnefort@arm.com

kernel/sched/core.c

@@ -6694,7 +6694,6 @@ void __init sched_init(void)
 
 		rq_attach_root(rq, &def_root_domain);
 #ifdef CONFIG_NO_HZ_COMMON
-		rq->last_load_update_tick = jiffies;
 		rq->last_blocked_load_update_tick = jiffies;
 		atomic_set(&rq->nohz_flags, 0);
 #endif

kernel/sched/sched.h

@@ -888,7 +888,6 @@ struct rq {
 #endif
 #ifdef CONFIG_NO_HZ_COMMON
 #ifdef CONFIG_SMP
-	unsigned long		last_load_update_tick;
 	unsigned long		last_blocked_load_update_tick;
 	unsigned int		has_blocked_load;
 #endif /* CONFIG_SMP */