Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/atm/common.c b/net/atm/common.c
index a38c174..0ce530a 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /* net/atm/common.c - ATM sockets (common part for PVC and SVC) */
 
 /* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
@@ -667,7 +668,7 @@
 		mask |= EPOLLHUP;
 
 	/* readable? */
-	if (!skb_queue_empty(&sk->sk_receive_queue))
+	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
 		mask |= EPOLLIN | EPOLLRDNORM;
 
 	/* writable? */