sched: Fix incorrect sleep duration in wait_task_inactive()

The sleep timeout in wait_task_inactive is incorrectly set to 10 usec
by 'commit e387fd87 ("sched: reduce sleep duration in
wait_task_inactive()")'. The intention of the patch was to use
1 msec like in previous kernel. The 10 usec is too short and won't
allow the other task to become inactive. This can potentially
result in a boot up failure while the creation of the smpboot
threads.

Change-Id: Ib888a0f4d70c13320b39847b5d3fca8ec1963e80
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>