[mutter] build: Fix non-wayland build

[Jasper St. Pierre <jstpierre src gnome org>]

commit 6b82f61dba6a569a5a2c240d08d3a600fd35b94d
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Wed Jun 17 18:37:20 2015 +0800

    build: Fix non-wayland build
    
    This fixes error introduced in 09120132ef87061d527b5324a14ab5950db3dc0a.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=750552

 src/core/window.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/core/window.c b/src/core/window.c
index 4443a24..aec61db 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -724,9 +724,11 @@ meta_window_should_attach_to_parent (MetaWindow *window)
 static gboolean
 client_window_should_be_mapped (MetaWindow *window)
 {
+#ifdef HAVE_WAYLAND
   if (window->client_type == META_WINDOW_CLIENT_TYPE_WAYLAND &&
       !window->surface->buffer)
     return FALSE;
+#endif
 
   return !window->shaded;
 }
@@ -1538,9 +1540,11 @@ meta_window_showing_on_its_workspace (MetaWindow *window)
 gboolean
 meta_window_should_be_showing (MetaWindow  *window)
 {
+#ifdef HAVE_WAYLAND
   if (window->client_type == META_WINDOW_CLIENT_TYPE_WAYLAND &&
       !window->surface->buffer)
     return FALSE;
+#endif
 
   /* Windows should be showing if they're located on the
    * active workspace and they're showing on their own workspace. */