[gtk] Fix XChangeProperty calls

[Matthias Clasen <matthiasc src gnome org>]

commit a80007ac12d22cd95c9c3b87174ba0e07d9f5b89
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Jan 2 19:26:56 2019 -0500

    Fix XChangeProperty calls
    
    They must be long...
    
    Closes: #1556

 gdk/x11/gdkdisplay-x11.c | 2 +-
 gdk/x11/gdksurface-x11.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/gdk/x11/gdkdisplay-x11.c b/gdk/x11/gdkdisplay-x11.c
index 848e41f68c..ca1237e703 100644
--- a/gdk/x11/gdkdisplay-x11.c
+++ b/gdk/x11/gdkdisplay-x11.c
@@ -1600,7 +1600,7 @@ gdk_x11_display_open (const gchar *display_name)
   if (!gdk_running_in_sandbox ())
     {
       /* if sandboxed, we're likely in a pid namespace and would only confuse the wm with this */
-      pid_t pid = getpid ();
+      long pid = getpid ();
       XChangeProperty (display_x11->xdisplay,
                        display_x11->leader_window,
                        gdk_x11_get_xatom_by_name_for_display (display, "_NET_WM_PID"),
diff --git a/gdk/x11/gdksurface-x11.c b/gdk/x11/gdksurface-x11.c
index 29b6dae9f7..a8a8140b2e 100644
--- a/gdk/x11/gdksurface-x11.c
+++ b/gdk/x11/gdksurface-x11.c
@@ -746,7 +746,7 @@ setup_toplevel_window (GdkSurface    *surface,
   if (!gdk_running_in_sandbox ())
     {
       /* if sandboxed, we're likely in a pid namespace and would only confuse the wm with this */
-      pid_t pid = getpid ();
+      long pid = getpid ();
       XChangeProperty (xdisplay, xid,
                        gdk_x11_get_xatom_by_name_for_display (x11_screen->display, "_NET_WM_PID"),
                        XA_CARDINAL, 32,