sched: change load balance number to h_nr_running of run queue

Date    Sun, 18 Aug 2013 16:25:15 +0800

Since rq->nr_running would include both migration and rt task, it is not
reasonable to seek to move nr_running number of task in the load_balance
function, since it only apply to cfs type.

Change it to cfs's h_nr_running, which could well present the task
number in current cfs queue.

Signed-off-by: Lei Wen <leiwen@marvell.com>
backported to Linux 3.4 by faux123
Signed-off-by: Paul Reioux <reioux@gmail.com>