[gnome-session] Fix use-after-free in initialize_gio()

[Ray Strode <halfline src gnome org>]

commit bc90e8679f9c6bf8af33125586da213cab5dcc59
Author: Tomas Popela <tpopela redhat com>
Date:   Thu Jun 29 14:30:16 2017 +0200

    Fix use-after-free in initialize_gio()
    
    Don't use already freed use_vfs variable in the fuse code, but use the
    disable_fuse one.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=784339

 gnome-session/main.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gnome-session/main.c b/gnome-session/main.c
index 89e8f3b..d28f0df 100644
--- a/gnome-session/main.c
+++ b/gnome-session/main.c
@@ -258,7 +258,7 @@ initialize_gio (void)
         }
 
         if (disable_fuse) {
-                g_setenv ("GVFS_DISABLE_FUSE", use_vfs, TRUE);
+                g_setenv ("GVFS_DISABLE_FUSE", disable_fuse, TRUE);
                 g_free (disable_fuse);
         } else {
                 g_unsetenv ("GVFS_DISABLE_FUSE");