modify FindIndex to compare uuids

modify FindIndex to compare uuids

If FindIndex is provided a server address and entry has a valid
uuid, obtain the uuid for 'server' and use that search for a
matching entry.

This modification is necessary in order to permit operations
against multi-homed servers in split horizon DNS configurations.

Reviewed-on: http://gerrit.openafs.org/3468
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 9aad0979e9ff0601c249eb66a6ecfb3e76264702)
Change-Id: If819975bd24e29da1142531c3f0eb27755e65afb
Reviewed-on: http://gerrit.openafs.org/3489