Fixup pylint issues

libagent/ssh/protocol.py

@@ -167,6 +167,6 @@ class Handler:
         return util.frame(code, data)
 
 
-def _unsupported_extension(buf):
+def _unsupported_extension(buf):  # pylint: disable=unused-argument
     code = util.pack('B', msg_code('SSH_AGENT_EXTENSION_FAILURE'))
     return util.frame(code)

libagent/ssh/tests/test_client.py

@@ -21,7 +21,7 @@ class MockDevice(device.interface.Device):  # pylint: disable=abstract-method
     def package_name(cls):
         return 'fake-device-agent'
 
-    def connect(self):  # pylint: disable=no-self-use
+    def connect(self):
         return mock.Mock()
 
     def pubkey(self, identity, ecdh=False):  # pylint: disable=unused-argument