[llvm] [MemProf] Fix bug introduced by restructuring in optional handling (PR #139092)

[Teresa Johnson via llvm-commits]

teresajohnson wrote:

@snehasish noticed this newly introduced bug when prepping a follow on change this morning, so I went ahead and merged the fix. Please do post-commit review when you get a chance and I'll address any feedback in a follow up PR

https://github.com/llvm/llvm-project/pull/139092