[Bug 39516] Listview tests consistently fail

https://bugs.winehq.org/show_bug.cgi?id=39516

--- Comment #6 from Nikolay Sivov  ---
(In reply to Piotr Caban from comment #5)
> Created attachment 52702 [details]
> flush events after SetForegroundWindow call
>
> This patch should fix the test failures, could you please give it a try?

Works fine here. No failures after 10 runs in a row. Without this flush it
fails every time. Thank you.