found by temporarily marking Reference as SAL_WARN_UNUSED.

Change-Id: I18809b62654467f890016adcc92576980ced393b
Reviewed-on: https://gerrit.libreoffice.org/37511Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>