regression from commit 65b7b632
"loplugin:unusedenumconstants read-only constants in vcl"

Change-Id: I262dd4c9cd1dc6eca82521f5fd9fbfc952fb7745
Reviewed-on: https://gerrit.libreoffice.org/41111Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>