[clang] [Clang-Tools][Windows] Fix driver name transformation in scan-build (PR #143135)

[Balazs Benics via cfe-commits]

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

I've never used scan-build on Windows, but the patch looks harmless so let's fix this.

https://github.com/llvm/llvm-project/pull/143135