[NFC][compiler-rt] Inclusive language: replace master/slave with primary/secondary

[NFC] As part of using inclusive language within the llvm project, this patch
replaces master and slave with primary and secondary respectively in
`sanitizer_mac.cpp`.

Reviewed By: ZarkoCA

Differential Revision: https://reviews.llvm.org/D114255

GitOrigin-RevId: 5c162ec54520114afd9ff0a53bcc5876747d4e94
1 file changed