Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index d86be8b..4a9a2f6 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -1,18 +1,5 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
- *   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
- *
  */
 
 #include <linux/gfp.h>
@@ -401,6 +388,9 @@
 		}
 
 		prepare_outbound_urb(ep, ctx);
+		/* can be stopped during prepare callback */
+		if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags)))
+			goto exit_clear;
 	} else {
 		retire_inbound_urb(ep, ctx);
 		/* can be stopped during retire callback */