The brick tags in the xml output of volume top commands are improperly nested or incorrectly closed when a brick does not contain any file(s)

Version: 3.4.0qa2

Sample results:

[root@dhcp159-18 vdsm.test6]# gluster volume top music2 open nfs --xml | xmllint --format -
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<cliOutput>
  <opRet>0</opRet>
  <opErrno>0</opErrno>
  <opErrstr/>
  <volTop>
    <brickCount>2</brickCount>
    <topOp>1</topOp>
    <brick>
      <name>localhost</name>
      <members>0</members>
      <currentOpen>0</currentOpen>
      <maxOpen>1</maxOpen>
      <maxOpenTime>2012-11-28 05:09:19.576519</maxOpenTime>
      <brick>
        <name>10.16.159.17</name>
        <members>0</members>
        <currentOpen>0</currentOpen>
        <maxOpen>0</maxOpen>
        <maxOpenTime>N/A</maxOpenTime>
      </brick>
    </brick>
  </volTop>
</cliOutput>