sched: Simplify can_migrate_task()

At this point tsk_cache_hot is always true, so no need to check it.
Signed-off-by: Zhang Hang <bob.zhanghang@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/51650107.9040606@huawei.com
[ Also remove unnecessary schedstat #ifdefs. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/sched/fair.c

@@ -3921,20 +3921,17 @@ int can_migrate_task(struct task_struct *p, struct lb_env *env)
 	tsk_cache_hot = task_hot(p, env->src_rq->clock_task, env->sd);
 	if (!tsk_cache_hot ||
 		env->sd->nr_balance_failed > env->sd->cache_nice_tries) {
-#ifdef CONFIG_SCHEDSTATS
+
 		if (tsk_cache_hot) {
 			schedstat_inc(env->sd, lb_hot_gained[env->idle]);
 			schedstat_inc(p, se.statistics.nr_forced_migrations);
 		}
-#endif
+
 		return 1;
 	}
 
-	if (tsk_cache_hot) {
 	schedstat_inc(p, se.statistics.nr_failed_migrations_hot);
 	return 0;
-	}
-	return 1;
 }
 
 /*