ws2_32/tests: Fix AcceptEx tests related to address length

[Marvin]

Hi,

While running your changed tests on Windows, I think I found new failures.
Being a bot and all I'm not very good at pattern recognition, so I might be
wrong, but could you please double-check?
Full results can be found at
https://newtestbot.winehq.org/JobDetails.pl?Key=4593

Your paranoid android.


=== wxppro (32 bit sock) ===
sock.c:557: Test failed: oob_server (af4): unexpectedly at the OOB mark: 0

=== w2008s64 (32 bit sock) ===
sock.c:557: Test failed: oob_server (750): unexpectedly at the OOB mark: 0
sock: unhandled exception c0000005 at 00000000

=== w2008s64 (64 bit sock) ===
sock.c:557: Test failed: oob_server (750): unexpectedly at the OOB mark: 0