Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/net/psample.h b/include/net/psample.h
index 9b80f81..68ae16b 100644
--- a/include/net/psample.h
+++ b/include/net/psample.h
@@ -3,7 +3,6 @@
 #define __NET_PSAMPLE_H
 
 #include <uapi/linux/psample.h>
-#include <linux/module.h>
 #include <linux/list.h>
 
 struct psample_group {
@@ -12,9 +11,11 @@
 	u32 group_num;
 	u32 refcount;
 	u32 seq;
+	struct rcu_head rcu;
 };
 
 struct psample_group *psample_group_get(struct net *net, u32 group_num);
+void psample_group_take(struct psample_group *group);
 void psample_group_put(struct psample_group *group);
 
 #if IS_ENABLED(CONFIG_PSAMPLE)