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, 3 insertions, 1 deletions

diff --git a/third_party/nix/src/nix/upgrade-nix.cc b/third_party/nix/src/nix/upgrade-nix.cc
index 49f8db3b5b5f..277d761ec581 100644
--- a/third_party/nix/src/nix/upgrade-nix.cc
+++ b/third_party/nix/src/nix/upgrade-nix.cc
@@ -52,7 +52,9 @@ struct CmdUpgradeNix : MixDryRun, StoreCommand {
   void run(ref<Store> store) override {
     evalSettings.pureEval = true;
 
-    if (profileDir == "") profileDir = getProfileDir(store);
+    if (profileDir == "") {
+      profileDir = getProfileDir(store);
+    }
 
     LOG(INFO) << "upgrading Nix in profile '" << profileDir << "'";