[mutter] core: fix build without wayland

[Victor Toso de Carvalho <victortoso src gnome org>]

commit f8eb05ca6dd37d4e869508d47a71a2c0c6760dfa
Author: Victor Toso <victortoso redhat com>
Date:   Thu May 12 09:28:26 2016 +0200

    core: fix build without wayland
    
    introduced by 806f930a161415366e44f42df667a07d453add74
    
    https://bugzilla.gnome.org/show_bug.cgi?id=766306

 src/core/events.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/core/events.c b/src/core/events.c
index 957e53f..70647ea 100644
--- a/src/core/events.c
+++ b/src/core/events.c
@@ -219,6 +219,7 @@ meta_display_handle_event (MetaDisplay        *display,
                                        clutter_input_device_get_device_id (source));
     }
 
+#ifdef HAVE_WAYLAND
   if (meta_is_wayland_compositor () && event->type == CLUTTER_MOTION)
     {
       MetaWaylandCompositor *compositor;
@@ -237,6 +238,7 @@ meta_display_handle_event (MetaDisplay        *display,
 
       display->monitor_cache_invalidated = TRUE;
     }
+#endif
 
   handle_idletime_for_event (event);