[clang] [clang] Fix --entry command line option (PR #69114)

[Tuur Martens via cfe-commits]

JohnyTheCarrot wrote:

Heya @MaskRay 

If and when you get the chance, would you mind giving it another look?
I applied your requested changes. :)

Thanks!

https://github.com/llvm/llvm-project/pull/69114