[gtk+] quartz: fix quartz build

[Christian Hergert <chergert src gnome org>]

commit 1bd5be6b7c54e28ba6c3e920f11ee2f369a3529c
Author: Christian Hergert <christian hergert me>
Date:   Thu Mar 17 21:18:58 2016 -0700

    quartz: fix quartz build
    
    More fallout from recent refactoring.
    
    See also b3860e407d3edb6f94d53269960c052756516aa2.

 gdk/quartz/gdkevents-quartz.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/gdk/quartz/gdkevents-quartz.c b/gdk/quartz/gdkevents-quartz.c
index c8f1c19..749cc02 100644
--- a/gdk/quartz/gdkevents-quartz.c
+++ b/gdk/quartz/gdkevents-quartz.c
@@ -921,6 +921,9 @@ fill_pinch_event (GdkWindow *window,
     FP_STATE_IDLE,
     FP_STATE_UPDATE
   } last_state = FP_STATE_IDLE;
+  GdkQuartzDeviceManagerCore *device_manager;
+
+  device_manager = GDK_QUARTZ_DEVICE_MANAGER_CORE (_gdk_display->device_manager);
 
   event->any.type = GDK_TOUCHPAD_PINCH;
   event->touchpad_pinch.window = window;
@@ -933,7 +936,7 @@ fill_pinch_event (GdkWindow *window,
   event->touchpad_pinch.n_fingers = 2;
   event->touchpad_pinch.dx = 0.0;
   event->touchpad_pinch.dy = 0.0;
-  gdk_event_set_device (event, _gdk_display->core_pointer);
+  gdk_event_set_device (event, device_manager->core_pointer);
 
   switch ([nsevent phase])
     {