sd: fix comparison between different enum types

found while changing base of SvxFrameDirectionItem to SfxEnumItem

> warning: comparison between ‘enum SvxFrameDirection’
> and ‘enum com::sun::star::text::WritingMode’ [-Wenum-compare]

Change-Id: Ide7c8193fd700f2503b05322f0d4d38f465b12c5
Reviewed-on: https://gerrit.libreoffice.org/35148Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

sd/source/ui/view/drviews3.cxx

@@ -966,7 +966,7 @@ void  DrawViewShell::GetRulerState(SfxItemSet& rSet)
                 if( aEditAttr.GetItemState( EE_PARA_WRITINGDIR ) >= SfxItemState::DEFAULT )
                 {
                     const SvxFrameDirectionItem& rItem = static_cast<const SvxFrameDirectionItem&>( aEditAttr.Get( EE_PARA_WRITINGDIR ) );
-                    rSet.Put(SfxBoolItem(SID_RULER_TEXT_RIGHT_TO_LEFT, rItem.GetValue() == css::text::WritingMode_RL_TB));
+                    rSet.Put(SfxBoolItem(SID_RULER_TEXT_RIGHT_TO_LEFT, rItem.GetValue() == FRMDIR_HORI_RIGHT_TOP));
                 }
             }
         }