[gtk/prop-list] expression: Correct an example in the docs

[Matthias Clasen <matthiasc src gnome org>]

commit cb15f6196a6b91a415f3bfd6e214f21892addf74
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Dec 18 17:36:48 2019 -0500

    expression: Correct an example in the docs

 gtk/gtkexpression.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gtk/gtkexpression.c b/gtk/gtkexpression.c
index 1cd2d98ef9..02a8d4779a 100644
--- a/gtk/gtkexpression.c
+++ b/gtk/gtkexpression.c
@@ -85,7 +85,7 @@
  * |[
  *   <closure type='gchararray' function='combine_args_somehow'>
  *     <constant type='gchararray'>File size:</constant>
- *     <lookup type='gint64' name='size'>myfile</lookup>
+ *     <lookup type='GFile' name='size'>myfile</lookup>
  *   </closure>
  * ]|
  */