Patch to make call to plugin's delete_port() when floatingip creation fails
after the plugin has created the port. These changes will eventually be
proposed upstream.

*** neutron-2015.1.2/neutron/db/l3_db.py	Tue Oct 13 10:35:16 2015
--- new/neutron/db/l3_db.py	Wed Jul 13 23:51:38 2016
***************
*** 954,963 ****
                  floating_ip_address=floating_ip_address,
                  floating_port_id=external_port['id'])
              fip['tenant_id'] = tenant_id
!             # Update association with internal port
!             # and define external IP address
!             self._update_fip_assoc(context, fip,
!                                    floatingip_db, external_port)
              context.session.add(floatingip_db)
  
          return self._make_floatingip_dict(floatingip_db)
--- 954,969 ----
                  floating_ip_address=floating_ip_address,
                  floating_port_id=external_port['id'])
              fip['tenant_id'] = tenant_id
!             try:
!                 # Update association with internal port
!                 # and define external IP address
!                 self._update_fip_assoc(context, fip,
!                                        floatingip_db, external_port)
!             except:
!                 with excutils.save_and_reraise_exception():
!                     self._core_plugin.delete_port(context.elevated(),
!                                                   external_port['id'],
!                                                   l3_port_check=False)
              context.session.add(floatingip_db)
  
          return self._make_floatingip_dict(floatingip_db)