ACPI: Remove deferred execution from global lock acquire wakeup path

On acquiring the ACPI global lock, if there were sleepers on the lock,
we used to use acpi_os_execute() to defer a thread which would signal
sleepers.  Now just signal the semaphore directly.

http://bugzilla.kernel.org/show_bug.cgi?id=5534#c159

Signed-off-by: Len Brown <len.brown@intel.com>