Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/include/linux/relay.h b/include/linux/relay.h
index e1bdf01..c759f96 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -66,7 +66,7 @@
 	struct kref kref;		/* channel refcount */
 	void *private_data;		/* for user-defined data */
 	size_t last_toobig;		/* tried to log event > subbuf size */
-	struct rchan_buf ** __percpu buf; /* per-cpu channel buffers */
+	struct rchan_buf * __percpu *buf; /* per-cpu channel buffers */
 	int is_global;			/* One global buffer ? */
 	struct list_head list;		/* for channel list */
 	struct dentry *parent;		/* parent dentry passed to open */