[gtk+] testheightforwidth: Add missing unref

[Daniel Boles <dboles src gnome org>]

commit 329006507911d97abc6f0b8f81c1ffdc840696df
Author: Daniel Boles <dboles src gnome org>
Date:   Mon Mar 6 20:57:17 2017 +0000

    testheightforwidth: Add missing unref

 tests/testheightforwidth.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/tests/testheightforwidth.c b/tests/testheightforwidth.c
index 295a5ca..e2701ba 100644
--- a/tests/testheightforwidth.c
+++ b/tests/testheightforwidth.c
@@ -936,7 +936,10 @@ test_clicked (GtkWidget     *button,
         {
           g_printerr ("GtkBuilder for interface \"%s\" returned error \"%s\"\n",
                       interface->name, error->message);
+
           g_error_free (error);
+          g_object_unref (builder);
+
           return;
         }