wifi: mac80211: mlme: unify assoc data event sending

There are a few cases where we send an event to cfg80211
manually, but ieee80211_destroy_assoc_data() also handles
the case of abandoning; some cases don't need an event
and success is handled yet differently.

Unify this by providing a single status argument to the
ieee80211_destroy_assoc_data() function and then handling
all the different cases of events (or no events) there.

This will help simplify the code when MLO support is
added.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>