[gtk/test-protocol] testsuite: Fix an a11y test

[Matthias Clasen <matthiasc src gnome org>]

commit 9eda6830608c682da4086921c5ff6fbb4c0efe41
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Mar 20 12:09:21 2020 -0400

    testsuite: Fix an a11y test
    
    The derive test wasn't producing TAP, so
    running it as part of a tap testsuite wasn't
    going well. Fix that.

 testsuite/a11y/derive.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)
---
diff --git a/testsuite/a11y/derive.c b/testsuite/a11y/derive.c
index b9e4d4d41c..a926074f4a 100644
--- a/testsuite/a11y/derive.c
+++ b/testsuite/a11y/derive.c
@@ -57,17 +57,24 @@ my_button_class_init (MyButtonClass *class)
                                         my_button_accessible_get_type ());
 }
 
-int main (int argc, char *argv[])
+static void
+test_derive (void)
 {
   GtkWidget *widget;
   GtkAccessible *accessible;
 
-  gtk_init ();
-
   widget = GTK_WIDGET (g_object_new (my_button_get_type (), NULL));
   accessible = GTK_ACCESSIBLE (gtk_widget_get_accessible (widget));
 
   g_assert (G_TYPE_CHECK_INSTANCE_TYPE (accessible, my_button_accessible_get_type ()));
+}
+
+int
+main (int argc, char *argv[])
+{
+  gtk_test_init (&argc, &argv, NULL);
+
+  g_test_add_func ("/derive", test_derive);
 
-  return 0;
+  return g_test_run ();
 }