The `.txt` here was unnecessary.
Fixes: d6abc1da "cmake: Add BSD-style licenses"
Signed-off-by: Simon McVittie <smcv@collabora.com>
# Copyright (c) 2008 Laurent Montel, <montel@kde.org>
# Copyright (c) 2013 Ralf Habacker, <ralf.habacker@freenet.de>
-# SPDX-License-Identifier: LicenseRef-CMakeScripts.txt
+# SPDX-License-Identifier: LicenseRef-CMakeScripts
#
# Redistribution and use is allowed according to the terms of the BSD license.
# For details see LICENSES/LicenseRef-CMakeScripts.txt.