Shut up an occaisonal buildbot error due to test files being left around.
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 6d7fe8e..40d7c3e 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -373,6 +373,14 @@
 
 class MakedirTests (unittest.TestCase):
     def setUp(self):
+        try:
+            os.rmdir(test_support.TESTFN)
+        except OSError:
+            pass
+        try:
+            os.unlink(test_support.TESTFN)
+        except OSError:
+            pass
         os.mkdir(test_support.TESTFN)
 
     def test_makedir(self):