Ensure we are very explicit about what we're comparing when

Ensure we are very explicit about what we're comparing when
we're comparing structures (ie. don't just do a memcmp). I
don't think this will fix the fcntl spin issue, but it's a
"just in case" change.
Jeremy.
(This used to be commit 41066208ad8ca20d35a32bdf9ad934e11465c8f1)