Confusing location of Ceres logic in LC0.DLL

[dje-dev]

Borg pointed out the one file that needs to be changed in the Leela source code tree is network_cudnn.cc. That is confusing because actually the Ceres addition to that code is currently hardwired to use CUDA and not CUDNN:

      _network[sessionIndex] = MakeCudaNetworkAuto(weights, od);

This is not an actual problem, just something confusing to be cleaned up.

[dje-dev]

Fixed with commit db92e8. The documentation page referenced the wrong c++ file.