[gnome-photos] print-preview: Sprinkle const

[Debarshi Ray <debarshir src gnome org>]

commit eb821b0c5f836db4fa379d64a573f86e0dde4868
Author: Debarshi Ray <debarshir gnome org>
Date:   Wed Mar 16 02:23:15 2016 +0100

    print-preview: Sprinkle const
    
    This keeps the code in sync with eog.

 src/photos-print-preview.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/photos-print-preview.c b/src/photos-print-preview.c
index bff3d85..1e71506 100644
--- a/src/photos-print-preview.c
+++ b/src/photos-print-preview.c
@@ -619,10 +619,10 @@ static gboolean
 press_inside_image_area (PhotosPrintPreview *preview, guint x, guint y)
 {
   PhotosPrintPreviewPrivate *priv;
+  const gint xs = (gint) x;
+  const gint ys = (gint) y;
   gint x0;
   gint y0;
-  gint xs = (gint) x;
-  gint ys = (gint) y;
 
   priv = preview->priv;
   get_current_image_coordinates (preview, &x0, &y0);