ACPICA: Fix code divergence of global lock handling

Commit 9cd0314(ACPI / ACPICA: Fix global lock acquisition) was backported
into ACPICA code base, and some divergence was introduced.

This patch fixed it,
- rename acpi_ev_global_lock_pending/acpi_ev_global_lock_pending_lock
  to acpi_gbl_global_lock_pending/acpi_gbl_global_lock_pending_lock.

- move the initialization of acpi_gbl_global_lock_pending_lock from
  acpi_ut_mutex_initialize to acpi_ev_init_global_lock_handler.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>