change name/role/roleTerm to xpath

simple xml inconsistencies 

This works
<mods:name type="personal">
    <mods:namePart type="given">Guizhi</mods:namePart>
    <mods:namePart type="family">Wang</mods:namePart>
    <role>
      <roleTerm authority="marcrelator" type="text">author</roleTerm>
    </role>
  </mods:name>


This doesn't work
  <mods:name type="personal">
    <mods:namePart type="given">Guizhi</mods:namePart>
    <mods:namePart type="family">Wang</mods:namePart>
    <mods:role>
      <mods:roleTerm authority="marcrelator" type="text">author</mods:roleTerm>
    </mods:role>
  </mods:name>