Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/lib/test_kmod.c b/lib/test_kmod.c
index d82d022..9cf7762 100644
--- a/lib/test_kmod.c
+++ b/lib/test_kmod.c
@@ -632,7 +632,7 @@
 	config->test_driver = NULL;
 
 	kfree_const(config->test_fs);
-	config->test_driver = NULL;
+	config->test_fs = NULL;
 }
 
 static void kmod_config_free(struct kmod_test_device *test_dev)