3ef790b9 accidentally dropped updating
LBS_DISPLAYCHANGED flag that had been done in LISTBOX_InvalidateItems()
if the count value was changed.
In fact, the newly added test shows LB_SETCOUNT message always causes
WM_DRAWITEM requests regardless of the count value.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=51591Signed-off-by: Akihiro Sagawa <sagawa.aki@gmail.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>