Eliminate GOTO statement in stats_clubb_utilities (#1233)
* Eliminate jump in stats_clubb_utilities CLUBB ticket #975
Hard removed end parameter from read call GOTO marker `100` removed since `end` parameter is gone and added output of read error code to help debugging.
Before this change, if the read encountered an EOF error and the jump to marker 100 happened, CLUBB would continue running (err_code=clubb_no_error) but no output files would be created. After this change, err_code will be set to clubb_fatal_error and CLUBB prints an error message and returns.