refactor(3p/nix): Apply clang-tidy's modernize-* fixes r/787

This applies the modernization fixes listed here:

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

The 'modernize-use-trailing-return-type' fix was excluded due to my
personal preference (more specifically, I think the 'auto' keyword is
misleading in that position).

1 files changed, 4 insertions, 3 deletions

diff --git a/third_party/nix/src/libstore/profiles.cc b/third_party/nix/src/libstore/profiles.cc
index 38ad0c01e461..3abdfaf1389f 100644
--- a/third_party/nix/src/libstore/profiles.cc
+++ b/third_party/nix/src/libstore/profiles.cc
@@ -1,8 +1,9 @@
 #include "profiles.hh"
 
-#include <errno.h>
+#include <cerrno>
+#include <cstdio>
+
 #include <glog/logging.h>
-#include <stdio.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -213,7 +214,7 @@ void deleteGenerationsOlderThan(const Path& profile, time_t t, bool dryRun) {
 
 void deleteGenerationsOlderThan(const Path& profile, const string& timeSpec,
                                 bool dryRun) {
-  time_t curTime = time(0);
+  time_t curTime = time(nullptr);
   string strDays = string(timeSpec, 0, timeSpec.size() - 1);
   int days;