smurf: Multi-threading smf_dataOrder_array was a bad idea...

Ignore any supplied WorkForce, since using multiple threads slows down
the re-ordered hugely rather than speeding it up - I presume because of
contention issues. I've tried ensuring that the output array is accessed
sequenctially but that does not seem to improve anything. I'm leaving the
multi-threaded infrastructure here, in case a better solution is ever
found.