Apply clang-format universally.

* It is tough to contribute to a project that doesn't use a formatter,
* It is extra hard to contribute to a project which has configured the formatter, but ignores it for some files
* Code formatting makes it harder to hide obscure / weird bugs by accident or on purpose,

Let's rip the bandaid off?

Note that PRs currently in flight should be able to be merged relatively easily by applying `clang-format` to their tip prior to merge.

Co-authored-by: Graham Christensen <graham@grahamc.com>

src/libutil/tee-logger.cc

@@ -104,4 +104,4 @@ makeTeeLogger(std::unique_ptr<Logger> mainLogger, std::vector<std::unique_ptr<Lo
     return std::make_unique<TeeLogger>(std::move(allLoggers));
 }
 
-}
+} // namespace nix