sched: Use this_rq() helper

It is a few instructions more efficent to and slightly more
readable to use this_rq()-> instead of cpu_rq(smp_processor_id())-> .

Size comparison of kernel/sched/fair.o:

   text    data     bss     dec     hex filename
  27972     122      26   28120    6dd8 fair.o.before
  27956     122      26   28104    6dc8 fair.o.after
Signed-off-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1368116643-87971-1-git-send-email-nzimmer@sgi.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -5418,10 +5418,9 @@ static inline void nohz_balance_exit_idle(int cpu)
 static inline void set_cpu_sd_state_busy(void)
 {
 	struct sched_domain *sd;
-	int cpu = smp_processor_id();
 
 	rcu_read_lock();
-	sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd);
+	sd = rcu_dereference_check_sched_domain(this_rq()->sd);
 
 	if (!sd || !sd->nohz_idle)
 		goto unlock;
@@ -5436,10 +5435,9 @@ static inline void set_cpu_sd_state_busy(void)
 void set_cpu_sd_state_idle(void)
 {
 	struct sched_domain *sd;
-	int cpu = smp_processor_id();
 
 	rcu_read_lock();
-	sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd);
+	sd = rcu_dereference_check_sched_domain(this_rq()->sd);
 
 	if (!sd || sd->nohz_idle)
 		goto unlock;

kernel/sched/rt.c

@@ -472,7 +472,7 @@ static int rt_se_boosted(struct sched_rt_entity *rt_se)
 #ifdef CONFIG_SMP
 static inline const struct cpumask *sched_rt_period_mask(void)
 {
-	return cpu_rq(smp_processor_id())->rd->span;
+	return this_rq()->rd->span;
 }
 #else
 static inline const struct cpumask *sched_rt_period_mask(void)