remove unused local variable

Change-Id: I8e2094060cf24b98109c20cb296f1b221343f1ac
diff --git a/neutron_tempest_plugin/services/network/json/network_client.py b/neutron_tempest_plugin/services/network/json/network_client.py
index f056c7f..0b2544b 100644
--- a/neutron_tempest_plugin/services/network/json/network_client.py
+++ b/neutron_tempest_plugin/services/network/json/network_client.py
@@ -952,8 +952,6 @@
         return service_client.ResponseBody(resp, body)
 
     def list_floatingips(self, **kwargs):
-        post_body = {'floatingips': kwargs}
-        body = jsonutils.dumps(post_body)
         uri = '%s/floatingips' % self.uri_prefix
         if kwargs:
             uri += '?' + urlparse.urlencode(kwargs, doseq=1)