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, 3 insertions, 2 deletions

diff --git a/third_party/nix/src/libstore/misc.cc b/third_party/nix/src/libstore/misc.cc
index 076c691b00..f95c4bec8b 100644
--- a/third_party/nix/src/libstore/misc.cc
+++ b/third_party/nix/src/libstore/misc.cc
@@ -171,8 +171,9 @@ void Store::queryMissing(const PathSet& targets, PathSet& willBuild_,
     }
   };
 
-  auto checkOutput = [&](const Path& drvPath, ref<Derivation> drv,
-                         const Path& outPath, ref<Sync<DrvState>> drvState_) {
+  auto checkOutput = [&](const Path& drvPath, const ref<Derivation>& drv,
+                         const Path& outPath,
+                         const ref<Sync<DrvState>>& drvState_) {
     if (drvState_->lock()->done) {
       return;
     }