[gtk+] gdkwindow-win32.c: Fix build on Visual C++

[Chun-wei Fan <fanchunwei src gnome org>]

commit 781846e5645cad1726718ad3527829c8451a724a
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Aug 6 13:06:35 2014 +0800

    gdkwindow-win32.c: Fix build on Visual C++
    
    Since MSVC is more strict about the types that we try to do a compare, cast
    old_ptr as HWND, as we know that it is a pointer...
    
    https://bugzilla.gnome.org/show_bug.cgi?id=733768

 gdk/win32/gdkwindow-win32.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gdk/win32/gdkwindow-win32.c b/gdk/win32/gdkwindow-win32.c
index 5f28496..d1652cf 100644
--- a/gdk/win32/gdkwindow-win32.c
+++ b/gdk/win32/gdkwindow-win32.c
@@ -1807,7 +1807,7 @@ gdk_win32_window_set_transient_for (GdkWindow *window,
   w32_error = GetLastError ();
 
   /* Don't re-set GWLP_HWNDPARENT to the same value */
-  if (old_ptr == parent_id && w32_error == NO_ERROR)
+  if ((HWND) old_ptr == parent_id && w32_error == NO_ERROR)
     return;
 
   /* Don't return if it failed, try SetWindowLongPtr() anyway */