sched/fair: Rename cfs_rq.nr_running into nr_queued

Rename cfs_rq.nr_running into cfs_rq.nr_queued which better reflects the
reality as the value includes both the ready to run tasks and the delayed
dequeue tasks.

Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://lore.kernel.org/r/20241202174606.4074512-10-vincent.guittot@linaro.org