Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/net/hamradio/hdlcdrv.c b/drivers/net/hamradio/hdlcdrv.c
index 97e3bc6..df495b5 100644
--- a/drivers/net/hamradio/hdlcdrv.c
+++ b/drivers/net/hamradio/hdlcdrv.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*****************************************************************************/
 
 /*
@@ -5,20 +6,6 @@
  *
  *	Copyright (C) 1996-2000  Thomas Sailer (sailer@ife.ee.ethz.ch)
  *
- *	This program is free software; you can redistribute it and/or modify
- *	it under the terms of the GNU General Public License as published by
- *	the Free Software Foundation; either version 2 of the License, or
- *	(at your option) any later version.
- *
- *	This program is distributed in the hope that it will be useful,
- *	but WITHOUT ANY WARRANTY; without even the implied warranty of
- *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *	GNU General Public License for more details.
- *
- *	You should have received a copy of the GNU General Public License
- *	along with this program; if not, write to the Free Software
- *	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
  *  Please note that the GPL allows you to use the driver, NOT the radio.
  *  In order to use the radio, you need a license from the communications
  *  authority of your country.
@@ -488,8 +475,7 @@
 
 	if (s->ops && s->ops->close)
 		i = s->ops->close(dev);
-	if (s->skb)
-		dev_kfree_skb(s->skb);
+	dev_kfree_skb(s->skb);
 	s->skb = NULL;
 	s->opened = 0;
 	return i;