Small fixes for modern flake8. (ros2#1264)

It doesn't like to compare types with ==, so switch to
isinstance as appropriate.

Signed-off-by: Chris Lalancette <clalancette@gmail.com>
Signed-off-by: Michael Carlstrom <rmc@carlstrom.com>

rclpy/test/test_logging_rosout.py

@@ -83,7 +83,7 @@ def test_enable_rosout(
 
     if expected_data:
         assert (rosout_subscription_msg is not None)
-        assert (type(rosout_subscription_msg) == Log)
+        assert (isinstance(rosout_subscription_msg, Log))
         assert (LoggingSeverity(rosout_subscription_msg.level) == LoggingSeverity.INFO)
         assert (len(rosout_subscription_msg.msg) != 0)
         assert (rosout_subscription_msg.msg == message_data)