Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/net/netrom.h b/include/net/netrom.h
index 5a0714f..80f15b1 100644
--- a/include/net/netrom.h
+++ b/include/net/netrom.h
@@ -266,7 +266,7 @@
 int nr_t1timer_running(struct sock *);
 
 /* sysctl_net_netrom.c */
-void nr_register_sysctl(void);
+int nr_register_sysctl(void);
 void nr_unregister_sysctl(void);
 
 #endif