updater: another place needs to handle additional dir level on windows

Change-Id: I04f784d317b8cfeea25932728f03c92b0b73c70e
diff --git a/bin/update/create_partial_update.py b/bin/update/create_partial_update.py
index e4005d5..694fbb2 100755
--- a/bin/update/create_partial_update.py
+++ b/bin/update/create_partial_update.py
@@ -116,6 +116,8 @@ def main():
    update_dir = updater_path.get_update_dir()

    current_build_path = add_single_dir(current_build_path)
    if sys.platform == "cygwin":
        current_build_path = add_single_dir(current_build_path)

    config = parse_config(update_config)