Rename scenario.manager._create_port to create_port

This is to:
1. Rename scenario.manager._create_port to create_port,
   because it is used by testcases outside the file.
2. Remove namestart parameter from _create_port, because
   name is not important for scenario testcases and to
   use class name as the prefix of port name will be more
   indicative.
3. Remove self.assertIsNotNone(result, 'Unable to allocate port')
   because when using expect_empty_body = False, it's impossible
   to get a None result.
   http://git.openstack.org/cgit/openstack/tempest/tree/tempest/lib/services/network/base.py#n66

Change-Id: Ia1be5af5b6be33e67c5a1256208c0272ae109b39
diff --git a/tempest/scenario/manager.py b/tempest/scenario/manager.py
index 4f7c090..4d7cee4 100644
--- a/tempest/scenario/manager.py
+++ b/tempest/scenario/manager.py
@@ -89,16 +89,14 @@
     # The create_[resource] functions only return body and discard the
     # resp part which is not used in scenario tests
 
-    def _create_port(self, network_id, client=None, namestart='port-quotatest',
-                     **kwargs):
+    def create_port(self, network_id, client=None, **kwargs):
         if not client:
             client = self.ports_client
-        name = data_utils.rand_name(namestart)
+        name = data_utils.rand_name(self.__class__.__name__)
         result = client.create_port(
             name=name,
             network_id=network_id,
             **kwargs)
-        self.assertIsNotNone(result, 'Unable to allocate port')
         port = result['port']
         self.addCleanup(test_utils.call_and_ignore_notfound_exc,
                         client.delete_port, port['id'])
@@ -147,8 +145,7 @@
         if vnic_type:
             ports = []
 
-            create_port_body = {'binding:vnic_type': vnic_type,
-                                'namestart': 'port-smoke'}
+            create_port_body = {'binding:vnic_type': vnic_type}
             if kwargs:
                 # Convert security group names to security group ids
                 # to pass to create_port
@@ -185,9 +182,9 @@
             for net in networks:
                 net_id = net.get('uuid', net.get('id'))
                 if 'port' not in net:
-                    port = self._create_port(network_id=net_id,
-                                             client=clients.ports_client,
-                                             **create_port_body)
+                    port = self.create_port(network_id=net_id,
+                                            client=clients.ports_client,
+                                            **create_port_body)
                     ports.append({'port': port['id']})
                 else:
                     ports.append({'port': net['port']})
diff --git a/tempest/scenario/test_network_basic_ops.py b/tempest/scenario/test_network_basic_ops.py
index 0c3bf23..1c4e262 100644
--- a/tempest/scenario/test_network_basic_ops.py
+++ b/tempest/scenario/test_network_basic_ops.py
@@ -113,7 +113,7 @@
         port_id = None
         if boot_with_port:
             # create a port on the network and boot with that
-            port_id = self._create_port(self.network['id'])['id']
+            port_id = self.create_port(self.network['id'])['id']
             self.ports.append({'port': port_id})
 
         server = self._create_server(self.network, port_id)