This patch adds protection around ACPI_CHECKSUM_ABORT so that ACPI
user space test utilities can re-define it for their own purposes
(currently used by ASLTS build environment).

This patch doesn't affect Linux kernel behavior.  Lv Zheng.
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>