build: Remove m4 macro defs which are not anymore used.
* configure.ac (GNUPG_FUNC_MKDIR_TAKES_ONE_ARG): Do not use. * acinclude.m4 (GNUPG_FUNC_MKDIR_TAKES_ONE_ARG): Remove unused macro defs. (GNUPG_CHECK_FAQPROG): Ditto. (GNUPG_CHECK_DOCBOOK_TO_TEXI): Ditto. (GNUPG_CHECK_MLOCK): Ditto.
- Signed-off-by: Werner Koch <wk@gnupg.org>