don't trust that this is what its supposed to be

Change-Id: If0450bdab2c315a94a75060e1fadf2f8513f9dae
(cherry picked from commit f792baef)

lotuswordpro/source/filter/lwpfribtable.cxx

@@ -72,7 +72,7 @@ void LwpFribTable::Read(LwpObjectStream* pObjStrm, sal_uInt16 /*len*/)
 
 LwpSuperTableLayout* LwpFribTable::GetSuperTable()
 {
-    return static_cast<LwpSuperTableLayout*>(m_objTable.obj().get());
+    return dynamic_cast<LwpSuperTableLayout*>(m_objTable.obj().get());
 }
 
 void LwpFribTable::RegisterNewStyle()