update_host_extattrs does an unnecessary search?

I c&p'ed some of the host search code, so it could work on an FQDN. This requires some footwork with views.
Chances are excellent if this method is being used, it's as part of a result from get_host_by_extattrs. Maybe require the update method to take a host reference instead of a hostname. Also is update the right word for this method? Maybe it should be set or clobber.