[clang] [clang][test] Fix cl-pathmap.c test failure on mac (PR #203043)

[Vladimir Vereschaka via cfe-commits]

https://github.com/vvereschaka approved this pull request.

Thank you @gulfemsavrun.
For some reason it didn't get reproduced on [llvm-clang-aarch64-darwin](https://lab.llvm.org/buildbot/#/builders/190) and I didn't update the test accordingly. 

https://github.com/llvm/llvm-project/pull/203043