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.

src/libstore/pathlocks.cc

@@ -6,7 +6,6 @@
 #include <cerrno>
 #include <cstdlib>
 
-
 namespace nix {
 
 PathLocks::PathLocks()
@@ -14,14 +13,12 @@ PathLocks::PathLocks()
 {
 }
 
-
 PathLocks::PathLocks(const PathSet & paths, const std::string & waitMsg)
     : deletePaths(false)
 {
     lockPaths(paths, waitMsg);
 }
 
-
 PathLocks::~PathLocks()
 {
     try {
@@ -31,11 +28,9 @@ PathLocks::~PathLocks()
     }
 }
 
-
 void PathLocks::setDeletion(bool deletePaths)
 {
     this->deletePaths = deletePaths;
 }
 
-
-}
+} // namespace nix