REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2040 Supports new logic which test current value before write new value. Only write new value when current value not same as new value. Signed-off-by: Eric Dong <eric.dong@intel.com> Reviewed-by: Ray Ni <ray.ni@intel.com> Acked-by: Laszlo Ersek <lersek@redhat.com>