[clang-tools-extra] [clang-tidy] Fix invalid fixit from modernize-use-ranges for nullptr used with std::unique_ptr (PR #127162)

[Congcong Cai via cfe-commits]

https://github.com/HerrCai0907 commented:

LGTM. since it is just a patch instead of ideal solution for `std::equality_comparable_with` stuff, could you add some FIXME in code?

https://github.com/llvm/llvm-project/pull/127162