Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/hwtracing/intel_th/pti.h b/drivers/hwtracing/intel_th/pti.h
index e9381ba..7dfc043 100644
--- a/drivers/hwtracing/intel_th/pti.h
+++ b/drivers/hwtracing/intel_th/pti.h
@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: GPL-2.0
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Intel(R) Trace Hub PTI output data structures
  *