build: Fix build with !HAVE_PTHREAD

Authored by gniibe on Aug 13 2019, 7:15 AM.

Description

build: Fix build with !HAVE_PTHREAD

* tests/t-lock.c [!HAVE_PTHREAD]: Buildable now.
  • GnuPG-bug-id: T4663
  • Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>