GdkSelectionOutputStreamX11: Plug a memory leak

gdk/x11/gdkselectionoutputstream-x11.c

@@ -93,6 +93,12 @@ gdk_x11_pending_selection_notify_new (Window window,
   return pending;
 }
 
+static void
+gdk_x11_pending_selection_notify_free (GdkX11PendingSelectionNotify *notify)
+{
+  g_slice_free (GdkX11PendingSelectionNotify, notify);
+}
+
 static void
 gdk_x11_pending_selection_notify_require (GdkX11PendingSelectionNotify *notify,
                                           guint                         n_sends)
@@ -145,6 +151,8 @@ gdk_x11_pending_selection_notify_send (GdkX11PendingSelectionNotify *notify,
                                       gdk_x11_get_xatom_name_for_display (display, notify->xevent.target),
                                       error));
     }
+
+  gdk_x11_pending_selection_notify_free (notify);
 }
 
 static gboolean