Fix texture destroy to TxdForceUnload

[G-Moris]

Fix for double deletion of an element

[tederis]

There's no double deletion. RwTextureDestroy internally decreases refs count. The existing code decreases refs by one at a time and deletes a texture when the counter gets zeroed.

[G-Moris]

During ForceUnload testing, a failure occurred in this part of the code.
If I can find a proper solution that accounts for all the edge cases, I might open a new PR.