Refactor test cases after adding new params to create_floatingip.

Change-Id: I1feaed67e46edce85397907528e23c4a5f487c1f
diff --git a/neutron_tempest_plugin/scenario/test_floatingip.py b/neutron_tempest_plugin/scenario/test_floatingip.py
index 504af12..a7eb58b 100644
--- a/neutron_tempest_plugin/scenario/test_floatingip.py
+++ b/neutron_tempest_plugin/scenario/test_floatingip.py
@@ -87,7 +87,7 @@
             network = self.network
         port = self.create_port(network, security_groups=[self.secgroup['id']])
         if create_floating_ip:
-            fip = self.create_and_associate_floatingip(port['id'])
+            fip = self.create_floatingip(port=port)
         else:
             fip = None
         server = self.create_server(