[gtk+/gtk-3-18] Clean up handling of _gdk_win32_grab_cursor

[Ignacio Casal Quinteiro <icq src gnome org>]

commit 3c54eb4c6e5f5142f3579b468ec7ab29d5f8df84
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Oct 17 12:45:25 2015 -0400

    Clean up handling of _gdk_win32_grab_cursor
    
    This is a variable holding a ref to an object, so it is
    a great case to use g_set_object and g_clear_object.
    
     # Please enter the commit message for your changes. Lines starting

 gdk/win32/gdkdevice-virtual.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/gdk/win32/gdkdevice-virtual.c b/gdk/win32/gdkdevice-virtual.c
index 3a97285..b947800 100644
--- a/gdk/win32/gdkdevice-virtual.c
+++ b/gdk/win32/gdkdevice-virtual.c
@@ -266,10 +266,9 @@ gdk_device_virtual_grab (GdkDevice    *device,
        {
          if (GetCursor () == GDK_WIN32_CURSOR (_gdk_win32_grab_cursor)->hcursor)
            SetCursor (NULL);
-         g_clear_object (&_gdk_win32_grab_cursor);
        }
 
-      _gdk_win32_grab_cursor = (cursor == NULL) ? NULL : g_object_ref (cursor);
+      g_set_object (&_gdk_win32_grab_cursor, cursor);
 
       if (_gdk_win32_grab_cursor != NULL)
        SetCursor (GDK_WIN32_CURSOR (_gdk_win32_grab_cursor)->hcursor);
@@ -303,9 +302,8 @@ gdk_device_virtual_ungrab (GdkDevice *device,
        {
          if (GetCursor () == GDK_WIN32_CURSOR (_gdk_win32_grab_cursor)->hcursor)
            SetCursor (NULL);
-         g_clear_object (&_gdk_win32_grab_cursor);
        }
-      _gdk_win32_grab_cursor = NULL;
+      g_clear_object (&_gdk_win32_grab_cursor);
 
       ReleaseCapture ();
     }