xend: Use vnc-listen setting specified in xend config file

If domU frame buffer configuration has no vnclisten attribute set, use
the global vnc-listen address specified in xend configuration file
when updating vfb location.  Currently the hardcoded value 'localhost'
is used.

Signed-off-by: Jim Fehlig <jfehlig@novell.com>

tools/python/xen/xend/XendDomainInfo.py

@@ -1410,7 +1410,8 @@ class XendDomainInfo:
             for dev_uuid, (dev_type, dev_info) in self.info['devices'].items():
                 if dev_type == 'vfb':
                     old_location = dev_info.get('location')
-                    listen_host = dev_info.get('vnclisten', 'localhost')
+                    listen_host = dev_info.get('vnclisten', \
+                                XendOptions.instance().get_vnclisten_address())
                     new_location = '%s:%s' % (listen_host, str(vnc_port))
                     if old_location == new_location:
                         break