Noticed while investigating the report about sortloot interacting
with persistent inventory window when identifying all of invent and
possibly skipping some items. [This doesn't fix that.]
End of game disclosure was using makeknown() on inventory. It is a
jacket around discover_object() which passes the flag to exercise
Wisdom. That's useless at end of game [now; conceivably wrong if
disclosure of characteristics exercise ever got added], so call
discover_object() directly to suppress exercise of Wisdom.
discover_object() was also calling update_inventory() for every item
being discovered. That's not useful when looping through inventory
at end of game.