D3D12 backend: fixed issue with the barriers when old and new states are the same (which may happen if present is called when no other commands were issued)
D3D12 backend: fixed issue with the barriers when old and new states are the same (which may happen if present is called when no other commands were issued)

DiligentGraphics/DiligentCore,DiligentGraphics/DiligentCore,DiligentGraphics/DiligentCore,DiligentGraphics/DiligentCore