Fix bug checking sloppy status, flush file

The check for not matching number of walkers was wrong. No accesses
the proper struct.

In case the job crashed ( and was not just aborted ) although we
write the data to file, it seems that they are not recoverable in
the fits file. I added a close and open call after each cycle/elapsed
time to write the file boundaries properly. There is a fits function
doing this, but it is not implemented in the slang wrapper.