sched: change find_busiest_queue to h_nr_running

Date    Sun, 18 Aug 2013 16:25:20 +0800

Since find_busiest_queue try to avoid do load balance for runqueue
which has only one cfs task and its load is above the imbalance
value calculated, we should use h_nr_running of cfs instead of
nr_running of rq.

Signed-off-by: Lei Wen <leiwen@marvell.com>
Signed-off-by: Paul Reioux <reioux@gmail.com>