Since only the xdg credentials file path is required, and
home_config_paths() is unable to construct the path ~/.git-credentials,
simplify the code by replacing home_config_paths() with
xdg_config_home().
Signed-off-by: NPaul Tan <pyokagan@gmail.com>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>