[llvm-branch-commits] [llvm-reduce] Remove outdated bugpoint comment (PR #214254)

[Aiden Grossman via llvm-branch-commits]

https://github.com/boomanaiden154 created https://github.com/llvm/llvm-project/pull/214254

Bugpoint was removed in 9d5574dda60151dcd1eb6f315c20e4d9120596f9. The
comment is also incorrect. llvm-reduce eventually subsumed bugpoint, not
the other way around.