Fix find available floating IP test

The test assumed that you were going to get back the IP that
you just created, but there may be another available IP on
that network, so just assert that the IP returned is available.

Change-Id: Ie47406c1e9839d4f82d789a6a39d9e970de72ee6

openstack/tests/functional/network/v2/test_floating_ip.py

@@ -123,7 +123,8 @@ class TestFloatingIP(base.BaseFunctionalTest):
 
     def test_find_available_ip(self):
         sot = self.conn.network.find_available_ip()
-        self.assertEqual(self.FIP_ID, sot.id)
+        self.assertIsNotNone(sot.id)
+        self.assertIsNone(sot.port_id)
 
     def test_get(self):
         sot = self.conn.network.get_ip(self.FIP_ID)