FlatOut2 demo calls FreeLibrary on the dinput8 module more times than
it has loaded it, and the module reference that the internal thread has
is getting decremented before its exit.

Having an internal window to destroy also makes it more likely to crash
as it takes more time to exit calls the window procedure function.

Waiting for the thread to complete when all the dinput instances are
destroyed ensures that the thread isn't alive when the game frees the
DLL, and prevents the thread from crashing.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=50673Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>