The imported algorithm is modified to match the tests.

Fixes a regression introduced by commit
671cf16f.

Windows inet_addr() behaves basically the same as Unix
inet_addr() which is different from inet_pton().
Signed-off-by: Paul Gofman <pgofman@codeweavers.com>
Signed-off-by: Zebediah Figura <zfigura@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>