[mutter] main: Fix compilation with wayland disabled

[Jonas Ådahl <jadahl src gnome org>]

commit ad7ec6b9792df829cb66e3c61f03abac07ba3799
Author: Jonas Ådahl <jadahl gmail com>
Date:   Thu Jul 21 18:26:08 2016 +0800

    main: Fix compilation with wayland disabled
    
    https://bugzilla.gnome.org/show_bug.cgi?id=769024

 src/core/main.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/core/main.c b/src/core/main.c
index c0a7aa5..bd81604 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -441,8 +441,10 @@ meta_init (void)
 
   calculate_compositor_configuration (&compositor_type, &backend_type);
 
+#ifdef HAVE_WAYLAND
   if (compositor_type == META_COMPOSITOR_TYPE_WAYLAND)
     meta_set_is_wayland_compositor (TRUE);
+#endif
 
   if (g_get_home_dir ())
     if (chdir (g_get_home_dir ()) < 0)