Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/net/ethernet/sfc/mtd.c b/drivers/net/ethernet/sfc/mtd.c
index 4ac30b6..273c08e 100644
--- a/drivers/net/ethernet/sfc/mtd.c
+++ b/drivers/net/ethernet/sfc/mtd.c
@@ -1,11 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /****************************************************************************
  * Driver for Solarflare network controllers and boards
  * Copyright 2005-2006 Fen Systems Ltd.
  * Copyright 2006-2013 Solarflare Communications Inc.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation, incorporated herein by reference.
  */
 
 #include <linux/module.h>
@@ -66,6 +63,9 @@
 
 		part->mtd.writesize = 1;
 
+		if (!(part->mtd.flags & MTD_NO_ERASE))
+			part->mtd.flags |= MTD_WRITEABLE;
+
 		part->mtd.owner = THIS_MODULE;
 		part->mtd.priv = efx;
 		part->mtd.name = part->name;