Update the code to better reflect recommended style:

Use != instead of <> since <> is documented as "obsolescent".
Use "is" and "is not" when comparing with None or type objects.
diff --git a/Lib/test/test_pty.py b/Lib/test/test_pty.py
index 53769c0..5ea7e6f 100644
--- a/Lib/test/test_pty.py
+++ b/Lib/test/test_pty.py
@@ -81,7 +81,7 @@
         raise TestFailed, "pty.fork() failed to make child a session leader."
     elif status / 256 == 3:
         raise TestFailed, "Child spawned by pty.fork() did not have a tty as stdout"
-    elif status / 256 <> 4:
+    elif status / 256 != 4:
         raise TestFailed, "pty.fork() failed for unknown reasons:"
         print os.read(master_fd, 65536)