Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/nds32/include/asm/swab.h b/arch/nds32/include/asm/swab.h
index e01a755..362a466 100644
--- a/arch/nds32/include/asm/swab.h
+++ b/arch/nds32/include/asm/swab.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 // Copyright (C) 2005-2017 Andes Technology Corporation
 
 #ifndef __NDS32_SWAB_H__