license: LGPL-2.1+ -> LGPL-2.1-or-later

Follow-up for db9ecf050165fd1033c6f81485917e229c4be537.
diff --git a/test/sd-script.py b/test/sd-script.py
index b41e359..c695c2e 100644
--- a/test/sd-script.py
+++ b/test/sd-script.py
@@ -1,5 +1,5 @@
 #!/usr/bin/env python3
-# SPDX-License-Identifier: LGPL-2.1+
+# SPDX-License-Identifier: LGPL-2.1-or-later
 #
 # sd-script.py: create LOTS of sd device entries in fake sysfs
 #