refactor(3p/nix): Apply clang-tidy's performance-* fixes r/789

This applies the performance fixes listed here:

https://clang.llvm.org/extra/clang-tidy/checks/list.html

1 files changed, 1 insertions, 1 deletions

diff --git a/third_party/nix/src/libstore/local-fs-store.cc b/third_party/nix/src/libstore/local-fs-store.cc
index 9a5ea153869a..2120afc0ce7c 100644
--- a/third_party/nix/src/libstore/local-fs-store.cc
+++ b/third_party/nix/src/libstore/local-fs-store.cc
@@ -12,7 +12,7 @@ LocalFSStore::LocalFSStore(const Params& params) : Store(params) {}
 struct LocalStoreAccessor : public FSAccessor {
   ref<LocalFSStore> store;
 
-  explicit LocalStoreAccessor(ref<LocalFSStore> store) : store(store) {}
+  explicit LocalStoreAccessor(const ref<LocalFSStore>& store) : store(store) {}
 
   Path toRealPath(const Path& path) {
     Path storePath = store->toStorePath(path);