Hammer on snapshot cd's

[Matthew Dillon]

:> This is depending a lot on the call graph analyser and without
:> optimising it simply isn't done.
:
:Ah nice! Compiling with -O2 revealed another one:

    Ach.  It sure did.  hammer_btree_iterate_reverse() is almost identical
    to hammer_btree_iterate().  It was exactly the same bug... a missing
    error assignment deep in a switch statement.

					-Matt