[gnome-builder] flatpak: Fix memory leak

[Matthew Leeds <mwleeds src gnome org>]

commit 0d79da583b1156d7daed76a79690b0e28250f615
Author: Matthew Leeds <mleeds redhat com>
Date:   Sun Apr 23 16:24:34 2017 -0500

    flatpak: Fix memory leak

 plugins/flatpak/gbp-flatpak-preferences-addin.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/plugins/flatpak/gbp-flatpak-preferences-addin.c b/plugins/flatpak/gbp-flatpak-preferences-addin.c
index 6ad7295..13ac300 100644
--- a/plugins/flatpak/gbp-flatpak-preferences-addin.c
+++ b/plugins/flatpak/gbp-flatpak-preferences-addin.c
@@ -142,8 +142,12 @@ contains_runtime (GPtrArray  *runtimes,
   for (guint i = 0; i < runtimes->len; i++)
     {
       FlatpakRef *existing_ref = g_ptr_array_index (runtimes, i);
-      if (g_strcmp0 (flatpak_ref_format_ref (existing_ref),
-                     flatpak_ref_format_ref (ref)) == 0)
+      g_autofree gchar *existing_ref_name = NULL;
+      g_autofree gchar *ref_name = NULL;
+
+      existing_ref_name = flatpak_ref_format_ref (existing_ref);
+      ref_name = flatpak_ref_format_ref (ref);
+      if (g_strcmp0 (existing_ref_name, ref_name) == 0)
         return TRUE;
     }