Fix COPY_FIRST_CANONNAME hostent search

In fake-addrinfo.c, the COPY_FIRST_CANONNAME logic erroneously assumes
that h_name is the same as h_aliases[0].  Look at h_name before
h_aliases for an FQDN, since h_name is normally the
forward-canonicalized name and h_aliases are not.

[ghudson@mit.edu: rewrote commit message]

ticket: 7556 (new)