[contrib][linux] Add SPDX-License-Identifier
diff --git a/contrib/linux-kernel/decompress_sources.h b/contrib/linux-kernel/decompress_sources.h
index 67d6b1f..907753e 100644
--- a/contrib/linux-kernel/decompress_sources.h
+++ b/contrib/linux-kernel/decompress_sources.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0-only
+/* SPDX-License-Identifier: GPL-2.0-only */
 
 /*
  * This file includes every .c file needed for decompression.
diff --git a/contrib/linux-kernel/linux_zstd.h b/contrib/linux-kernel/linux_zstd.h
index b926840..dcd1ec1 100644
--- a/contrib/linux-kernel/linux_zstd.h
+++ b/contrib/linux-kernel/linux_zstd.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
 /*
  * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
  * All rights reserved.