[mesh] Fix MeshTaichi warnings in CUDA backend (#6369)
[mesh] Fix MeshTaichi warnings in CUDA backend (#6369)

continue from: https://github.com/taichi-dev/taichi/pull/6306

Co-authored-by: pre-commit-ci[bot] <3ea08453efb076ca910552532a53973a6527df40@users.noreply.github.com>
yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi,yuanming-hu/taichi