cppcheck: operator "=" should return TableReference&

Change-Id: Ifefa4a314fbe9380332fd02c5fc8dfbb68e09cf5
diff --git a/sw/source/filter/ww8/docxattributeoutput.hxx b/sw/source/filter/ww8/docxattributeoutput.hxx
index d215607..04770c5 100644
--- a/sw/source/filter/ww8/docxattributeoutput.hxx
+++ b/sw/source/filter/ww8/docxattributeoutput.hxx
@@ -124,7 +124,7 @@ struct TableReference
    {
    }

    TableReference operator= (const TableReference& rhs)
    TableReference& operator= (const TableReference& rhs)
    {
        m_bTableCellOpen = rhs.m_bTableCellOpen ;
        m_nTableDepth    = rhs.m_nTableDepth ;