[lld] [lld][MachO] Silence warnings about --read-workers parsing (PR #156608)

[Frederik Harwath via llvm-commits]

frederik-h wrote:

> Thanks for picking this up @frederik-h. If this is giving a warning the code just after it for OPT_threads_eq should be as well as I copied it. 

No, that's fine because `unsigned threads` can become 0 during the parsing and that code tests for `threads == 0` instead of `threads < 0`.

> Also, while you're changing at this code, perhaps the variable name should be "workers" not "threads".

Done.


https://github.com/llvm/llvm-project/pull/156608