wined3d: don't update the screen when gdi back buffers are unlocked

Wed Apr 8 16:28:42 CDT 2009

Am Mittwoch, 8. April 2009 17:12:01 schrieb Vincent Povirk:
> This should fix bug 15789.

> And he tells me that he's too busy to send the change in, and I should do
> it if I want it to happen soon.
Well, the main reason is that I don't have the games in question to test the 
patch myself.

The same problem occurs in RealizePalette by the way. Otherwise the patch 
looks good to me