The helper function removes code duplication from tests that want to
initialize unix socket address to an absolute file path, derived from
current working directory of the test + relative filename of a resulting
socket. Because the former code used cwd = get_current_dir_name() as
part of absolute filename generation, the resulting filepath could later
cause failure of bind systcall due to unchecked permissions and
introduce confusing permission errors.
Signed-off-by: Valeriy Vdovin <valeriy.vdovin@virtuozzo.com>
fa705e418b