tdf#91837: fix deinitializeControls (forms)

m_bControlsInitialized wasn't ever resetted to false

Change-Id: I9f7bd6504ccaa0a41c9cb075c1ba33436f0f97dc
Reviewed-on: https://gerrit.libreoffice.org/60059
Tested-by: Jenkins
Reviewed-by: Lionel Elie Mamane <lionel@mamane.lu>

svx/source/form/formcontroller.cxx

@@ -325,6 +325,7 @@ void ColumnInfoCache::deinitializeControls()
     {
         lcl_resetColumnControlInfo( *col );
     }
+    m_bControlsInitialized = false;
 }