Remove unnecessary return statements

If they're at the end of a function/method and don't return a value,
then it's superfluous

Change-Id: Ibd8d43a15ee83cf51c5b7cea0b1cb6ea13d1357d

nova/rpc/amqp.py

@@ -272,7 +272,6 @@ class ProxyCallback(object):
             LOG.exception('Exception during message handling')
             ctxt.reply(None, sys.exc_info(),
                        connection_pool=self.connection_pool)
-        return
 
 
 class MulticallWaiter(object):

nova/tests/test_api.py

@@ -475,8 +475,6 @@ class ApiEc2TestCase(test.TestCase):
         self.assertEqual(len(rv), 1)
         self.assertEqual(rv[0].name, 'default')
 
-        return
-
     def test_authorize_revoke_security_group_cidr_v6(self):
         """
         Test that we can add and remove CIDR based rules
@@ -529,8 +527,6 @@ class ApiEc2TestCase(test.TestCase):
         self.assertEqual(len(rv), 1)
         self.assertEqual(rv[0].name, 'default')
 
-        return
-
     def test_authorize_revoke_security_group_foreign_group(self):
         """
         Test that we can grant and revoke another security group access

nova/tests/test_netapp.py

@@ -617,7 +617,6 @@ class FakeDfmServerHandler(BaseHTTPServer.BaseHTTPRequestHandler):
             out.write('</operation>')
         out.write('</binding>')
         out.write(WSDL_TRAILER)
-        return
 
     def do_POST(s):
         """Respond to a POST request."""
@@ -825,7 +824,6 @@ class FakeDfmServerHandler(BaseHTTPServer.BaseHTTPRequestHandler):
         s.wfile.write(RESPONSE_PREFIX)
         s.wfile.write(body)
         s.wfile.write(RESPONSE_SUFFIX)
-        return
 
 
 class FakeHttplibSocket(object):