Make cuda search process of cpp extension quiet (#32620)
Summary:
Fixes https://discuss.pytorch.org/t/error-with-cpp-extentions/67559.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32620
Differential Revision: D19576164
Pulled By: soumith
fbshipit-source-id: 076229322375774bec03ef2632fc233000c15391
