[FuzzerUtil] Partially revert D38481 on FuzzerUtil

This is because lib/Fuzzer doesn't really depend on llvm infrastucture.
It's not easy to access the llvm hardware_concurrency here.

Differential Reivision: https://reviews.llvm.org/D38481

git-svn-id: svn://svn.chromium.org/llvm-project/llvm/trunk/lib/Fuzzer@314870 0b72dbe1-c17f-4bc7-b9db-2b4152be0356
1 file changed