casctl: Fix license tag

Open CAS Linux and other projects in the Open CAS repo were always intended
to be released under the OSI-approved BSD 3-Clause License.
Change the license tag to the proper one.

Signed-off-by: Robert Baldyga <robert.baldyga@intel.com>

utils/casctl

@@ -1,7 +1,7 @@
 #!/usr/bin/env python3
 #
 # Copyright(c) 2012-2021 Intel Corporation
-# SPDX-License-Identifier: BSD-3-Clause-Clear
+# SPDX-License-Identifier: BSD-3-Clause
 #
 
 import argparse