ACPICA: Events: Fix acpi_ev_initialize_region() return value

ACPICA: Events: Fix acpi_ev_initialize_region() return value

ACPICA commit 543342ab7a676f4eb0c9f100d349388a84dff0e8

This patch changes acpi_ev_initialize_region(), stop returning AE_NOT_EXIST
from it so that, not only in acpi_ds_load2_end_op(), but all places invoking
this function won't emit exceptions. The exception can be seen in
acpi_ds_initialize_objects() when certain table loading mode is chosen.

This patch also removes useless acpi_ns_locked from acpi_ev_initialize_region()
as this function will always be invoked with interpreter lock held now, and
the lock granularity has been tuned to lock around _REG execution, thus it
is now handled by acpi_ex_exit_interpreter(). Lv Zheng.

Link: https://github.com/acpica/acpica/commit/543342ab
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>