Fixed typo in comment.
crash_stack_print_decorated(): declared "success" as volatile for longjmp().
Allow xfl_find_freelist_index() to work with gcc 4.9 and optimizations.

This is a workaround for a probable compiler bug.
keys_offload(): do not process if the key layer was shutdown.
dht_close(): added comment about why we save the old DHT boot status.

Also moved the DHT boot status change to the beginning of the routine.