Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/um/drivers/harddog_kern.c b/arch/um/drivers/harddog_kern.c
index 6d38127..000cb69 100644
--- a/arch/um/drivers/harddog_kern.c
+++ b/arch/um/drivers/harddog_kern.c
@@ -85,7 +85,7 @@
 	timer_alive = 1;
 	spin_unlock(&lock);
 	mutex_unlock(&harddog_mutex);
-	return nonseekable_open(inode, file);
+	return stream_open(inode, file);
 err:
 	spin_unlock(&lock);
 	mutex_unlock(&harddog_mutex);