style(3p/nix): Add braces around single-line conditionals r/771

These were not caught by the previous clang-tidy invocation, but were
instead sorted out using amber[0] as such:

    ambr --regex 'if (\(.+\))\s([a-z].*;)' 'if $1 { $2 }'

[0]: https://github.com/dalance/amber

1 files changed, 9 insertions, 3 deletions

diff --git a/third_party/nix/src/libutil/pool.hh b/third_party/nix/src/libutil/pool.hh
index e25d82d8ec..6d70795d35 100644
--- a/third_party/nix/src/libutil/pool.hh
+++ b/third_party/nix/src/libutil/pool.hh
@@ -99,10 +99,14 @@ class Pool {
     Handle(const Handle& l) = delete;
 
     ~Handle() {
-      if (!r) return;
+      if (!r) {
+        return;
+      }
       {
         auto state_(pool.state.lock());
-        if (!bad) state_->idle.push_back(ref<R>(r));
+        if (!bad) {
+          state_->idle.push_back(ref<R>(r));
+        }
         assert(state_->inUse);
         state_->inUse--;
       }
@@ -160,7 +164,9 @@ class Pool {
     auto state_(state.lock());
     std::vector<ref<R>> left;
     for (auto& p : state_->idle)
-      if (validator(p)) left.push_back(p);
+      if (validator(p)) {
+        left.push_back(p);
+      }
     std::swap(state_->idle, left);
   }
 };