According to the GNU Coding Standards[1], private executables should be
installed to libexecdir, not libdir.
Move privatedir to libexecdir.
[1] https://www.gnu.org/prep/standards/
https://bugs.freedesktop.org/show_bug.cgi?id=98817
AC_DEFINE_UNQUOTED(SHLEXT, ["$SHLEXT"], [File extension for shared libraries])
AC_SUBST(SHLEXT)
-privatedir='${libdir}/p11-kit'
+privatedir='${libexecdir}/p11-kit'
AC_SUBST(privatedir)
AC_CONFIG_FILES([Makefile