ACPI, APEI, Use apei_exec_run_optional in APEI EINJ and ERST

This patch changes APEI EINJ and ERST to use apei_exec_run for
mandatory actions, and apei_exec_run_optional for optional actions.

Cc: Thomas Renninger <trenn@novell.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>