[ofa-general] ib-diag: use of getpass()

[Sean Hefty]

>There was a thread on this back in June 2008:
>http://lists.openfabrics.org/pipermail/general/2008-June/051057.html
>
>Sasha wrote:
>glibc info page doesn't indicate this. Also I did some
>googling and looked at glibc code itself - found nothing suspicious yet.
>Finally it is how password handled in 'su'.

I'll add an implementation for it on windows then...