bpo-35994: add sub dir for sub2_tree in os.walk test if symlink is not supported (GH-11853)


https://bugs.python.org/issue35994
(cherry picked from commit 3e028b2d40370dc986b6f3146a7ae927bc119f97)

Co-authored-by: pxinwr <peixing.xin@windriver.com>
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index a50eb7e..ff22fbe 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -923,7 +923,7 @@
                               ["broken_link", "broken_link2", "broken_link3",
                                "tmp3"])
         else:
-            self.sub2_tree = (sub2_path, [], ["tmp3"])
+            self.sub2_tree = (sub2_path, ["SUB21"], ["tmp3"])
 
         os.chmod(sub21_path, 0)
         try: