[UT] OVN fake resources factory method should return instance

The OVN fake resources factory method should return an instance
of the requested object, not a "type" metaclass object.

Closes-Bug: #2047049
Change-Id: I85c613dd628d7d2b67446d999b3e4d7b91eaf9fe
(cherry picked from commit e45c403)

Author: ralonsoh

neutron/tests/unit/fake_resources.py

@@ -767,7 +767,7 @@ def create_one_port(attrs=None):
 
         # Overwrite default attributes.
         port_attrs.update(attrs)
-        return type('Logical_Switch_Port', (object, ), port_attrs)
+        return type('Logical_Switch_Port', (object, ), port_attrs)()
 
     @staticmethod
     def from_neutron_port(port):
@@ -810,7 +810,7 @@ def create_one_router(attrs=None):
 
         # Overwrite default attributes.
         router_attrs.update(attrs)
-        return type('Logical_Router', (object, ), router_attrs)
+        return type('Logical_Router', (object, ), router_attrs)()
 
     @staticmethod
     def from_neutron_router(router):
@@ -910,4 +910,4 @@ def create(attrs=None, az_list=None, chassis_as_gw=False,
 
         # Overwrite default attributes.
         chassis_attrs.update(attrs or {})
-        return type('Chassis', (object, ), chassis_attrs)
+        return type('Chassis', (object, ), chassis_attrs)()