common: Allow building of mkdir_p.c for Windows.
* common/mkdir_p.c: Change license and comment debug statements. (amkdir_p, mkdir_p): Fail on malloc error and use default_errsource to build an error code. Change return value to gpg_error_t. (amkdir_p): Use gnupg_mkdir. * common/membuf.c: Include util.h first to avoid redefined macro warnings.
- Signed-off-by: Werner Koch <wk@gnupg.org>