ACPICA: Events: Fix an issue that region object is re-attached to another...

ACPICA: Events: Fix an issue that region object is re-attached to another scope when it is already attached

ACPICA commit 6ebcb24d3225b6c7715a3ce061c327b4c3a6b76e

The logic in acpi_ev_attach_region() is not correct, it can break address
space handler link. This patch fixes this problem. But be aware that this
fix must be applied along with a region object race issue fix. Lv Zheng.

Link: https://github.com/acpica/acpica/commit/6ebcb24d


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>