Hack to make the previous bug work

[Arun Welch <welch@cis.ohio-state.edu>]

(setf (slot-value fifi 'ears) 4) expands into (set-slot-value fifi
'ears 4), so using the latter instead works.  Obviously not a
long-term solution, but if you're really need to give fifi 4 ears, it works.

...arun