a) There was a case where a ICMP message could cause
us to return leaving a stuck lock on an stcb.
b) The iterator needed some tweaks to fix its lock
ordering.
c) The ITERATOR_LOCK is no longer needed in the freeing
of a stcb. Now that the timer based one is gone we don't
have a multiple resume situation. Add to that that there
was somewhere a path out of the freeing of an assoc that
did NOT release the iterator_lock.. it was time to clean
this old code up and in the process fix the lock bug.
MFC after: 1 week
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