viced: host hash address collisions

viced: host hash address collisions

Attempt to resolve collisions when adding a host to the
address hash table and another host with the same address:port
is already present in the hash table. Retrieve the uuid for
the host at that address and if the uuid matches the new host
and not the old, remove the address from the old host and
install the new host into the address hash.

Change-Id: Id182f907f63be556c61ffb91777edd35f0aa950d
Reviewed-on: http://gerrit.openafs.org/1786
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Tested-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>