[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: https://llvm.org/svn/llvm-project/llvm/trunk@314870 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed