[mutter] wayland: Avoid GVariant leak in set_gnome_env

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit a63e80ec64be268c2ed9883dd871aeaab39de9e5
Author: Sebastian Keller <skeller gnome org>
Date:   Fri Jan 24 18:47:43 2020 +0100

    wayland: Avoid GVariant leak in set_gnome_env
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/1020

 src/wayland/meta-wayland.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/wayland/meta-wayland.c b/src/wayland/meta-wayland.c
index 806c897c9..876b4925a 100644
--- a/src/wayland/meta-wayland.c
+++ b/src/wayland/meta-wayland.c
@@ -266,13 +266,14 @@ set_gnome_env (const char *name,
 {
   GDBusConnection *session_bus;
   GError *error = NULL;
+  g_autoptr (GVariant) result = NULL;
 
   setenv (name, value, TRUE);
 
   session_bus = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, NULL);
   g_assert (session_bus);
 
-  g_dbus_connection_call_sync (session_bus,
+  result = g_dbus_connection_call_sync (session_bus,
                               "org.gnome.SessionManager",
                               "/org/gnome/SessionManager",
                               "org.gnome.SessionManager",