Fix typo in ceilometer-cinder.rst
Fix typo in ceilometer-cinder.rst

- remove '</programlisting>' from
  notification_driver = messagingv2</programlisting>

Closes-Bug: #1510633
Change-Id: I574fdca330f0a0433804f4435f2721044afbd7d8

openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals