Verify buffer support for error log.

Added Unit Tests to verify that a caller buffer is propageted
to the error log through an FAPI_INVOKE_HWP call. The Unit Tests
use both a fapi2::buffer<uin64_t> and a fapi2::variable_buffer types.
Presently, support for using fapi2::variable_buffer is disabled in
the code base. The unit tests for the variable_buffer is also disabled.
To enable fapi2::variable buffer support the parseErrorInfo.pl script
must be invoked with the --use_variable_buffers option. This can be
done by adding the --use_variable_buffers option to the
parseErrorInfo_RUN macro located in
import/hwpf/fapi2/tools/parseErrorInfo.mk.

RTC: 161195
Change-Id: I0e372dc72e749f635517eb1752e3ca1ec4d2195b
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/41310
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Reviewed-by: Prachi Gupta <pragupta@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: William G. Hoffa <wghoffa@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>