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, 6 insertions, 2 deletions

diff --git a/third_party/nix/src/libstore/globals.cc b/third_party/nix/src/libstore/globals.cc
index bbcf63a6f5..4d502c0ade 100644
--- a/third_party/nix/src/libstore/globals.cc
+++ b/third_party/nix/src/libstore/globals.cc
@@ -98,7 +98,9 @@ StringSet Settings::getDefaultSystemFeatures() {
   StringSet features{"nixos-test", "benchmark", "big-parallel"};
 
 #if __linux__
-  if (access("/dev/kvm", R_OK | W_OK) == 0) features.insert("kvm");
+  if (access("/dev/kvm", R_OK | W_OK) == 0) {
+    features.insert("kvm");
+  }
 #endif
 
   return features;
@@ -171,7 +173,9 @@ void initPlugins() {
       for (const auto& ent : ents)
         pluginFiles.emplace_back(pluginFile + "/" + ent.name);
     } catch (SysError& e) {
-      if (e.errNo != ENOTDIR) throw;
+      if (e.errNo != ENOTDIR) {
+        throw;
+      }
       pluginFiles.emplace_back(pluginFile);
     }
     for (const auto& file : pluginFiles) {