[gtk/wip/baedert/for-master] testtreeview: Properly annotate a switch fallthrough

[Timm Bäder <baedert src gnome org>]

commit b13f49b8ae52c8b398aae7001f22ae4a5580eb8c
Author: Timm Bäder <mail baedert org>
Date:   Wed May 6 12:34:56 2020 +0200

    testtreeview: Properly annotate a switch fallthrough

 tests/testtreeview.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/testtreeview.c b/tests/testtreeview.c
index a5648c6be9..0715c449f4 100644
--- a/tests/testtreeview.c
+++ b/tests/testtreeview.c
@@ -448,7 +448,7 @@ set_columns_type (GtkTreeView *tree_view, ColumnsType type)
       
 #endif
       
-      /* FALL THRU */
+      G_GNUC_FALLTHROUGH;
       
     case COLUMNS_ONE:
       rend = gtk_cell_renderer_text_new ();