[mutter] wayland: Fix up touch coordinates on HiDPI

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

commit 91ac69382d5c6e9675c360e7f8f93aa362a191e0
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Mon Dec 14 14:52:23 2015 -0800

    wayland: Fix up touch coordinates on HiDPI

 src/wayland/meta-wayland-touch.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/wayland/meta-wayland-touch.c b/src/wayland/meta-wayland-touch.c
index 2892510..2ec9dce 100644
--- a/src/wayland/meta-wayland-touch.c
+++ b/src/wayland/meta-wayland-touch.c
@@ -208,8 +208,8 @@ touch_get_relative_coordinates (MetaWaylandTouch   *touch,
                                            &event_x, &event_y);
     }
 
-  *x = event_x;
-  *y = event_y;
+  *x = event_x / surface->scale;
+  *y = event_y / surface->scale;
 }