Fix Cannot convert unsigned long* in sal_uLong*

Change-Id: I7e44ea91f1202d70ddc4f16aed5890f14f2b2f64
Reviewed-on: https://gerrit.libreoffice.org/13287
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>
Tested-by: Stephan Bergmann <sbergman@redhat.com>