[llvm] [llvm-mc-assemble-fuzzer] Fix Triple passing (PR #181135)

[Aiden Grossman via llvm-commits]

https://github.com/boomanaiden154 approved this pull request.

This isn't built by default anywhere for this to be detected? That kind of seems like a problem.

Fix LGTM though.

https://github.com/llvm/llvm-project/pull/181135