net/tcp_ao: Don't leak ao_info on error-path
In the Linux kernel, the following vulnerability has been resolved:

net/tcp_ao: Don't leak ao_info on error-path

It seems I introduced it together with TCP_AO_CMDF_AO_REQUIRED, on
version 5 [1] of TCP-AO patches. Quite frustrative that having all these
selftests that I've written, running kmemtest & kcov was always in todo.

[1]: https://lore.kernel.org/netdev/20230215183335.800122-5-dima@arista.com/