olepicture: ref count cleanup

[Alexandre Julliard]

James Hawkins <truiken at gmail.com> writes:

> Changelog
>    * Use InterlockedDecrement and InterlockedIncrement instead of ++/--.

When making these changes please fix the rest of the function too, any
place that uses This->ref directly is broken, it should use the return
value of the Interlocked call instead. Otherwise there's no point in
making the changes since it still won't be thread-safe.

-- 
Alexandre Julliard
julliard at winehq.org