explicitly check or discard cudaGetLastError return value (#100488)
cudaGetLastError and hipGetLastError will clear any error value within CUDA and HIP, respectively. This is often done on purpose to clear benign errors. Discarding the return value should be indicated by casting to void and a nearby comment. This silences warnings from HIP:
warning: ignoring return value of function declared with 'nodiscard' attribute [-Wunused-result]
Performing an audit of pytorch sources found one use of cudaGetLastError that was incorrectly ignored in IndexKernel.cu.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/100488
Approved by: https://github.com/ezyang
