Fix hardclock with some versions of mingw64

Backport of 383433535 from the 1.3 branch
diff --git a/ChangeLog b/ChangeLog
index 69ecd60..3a4522c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -7,6 +7,8 @@
      crash it remotely (found by Caj Larsson).
 
 Bugfix
+   * Fix hardclock() (only used in the benchmarking program) with some
+     versions of mingw64 (found by kxjhlele).
    * Fix warnings from mingw64 in timing.c (found by kxjklele).
    * Fix potential unintended sign extension in asn1_get_len() on 64-bit
      platforms (found with Coverity Scan).