ACPICA: Regression fix: reinstate safe exit macros

Removal caused a regression on at least FreeBSD. This fix
reinstates the macros.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>