Now that freezer_count() and freezer_do_not_count() don't have the restriction
that they are effective only when called by userspace processes, use
them in lock_system_sleep() and unlock_system_sleep() instead of open-coding
their parts.
Signed-off-by: NSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>