Error with getic task if ROTDIR directory not cleaned up

[jkhender]

Expected behavior
User should not have to clean up $ROTDIR before running getic again after it fails

Current behavior
After I ran the getic task and it failed (see issue #1155), the job was resubmitted. The job gave an error when running the following statement.

mv ${EXTRACT_DIR}/${CDUMP}.${yy}${mm}${dd}/${hh}/* ${ROTDIR}/${CDUMP}.${yy}${mm}${dd}/${hh}

mv: cannot move <EXTRACT_DIR>/gfs.20221115/00/* to <ROT_DIR>/gfs.20221115/00/atmos': Directory not empty

Machines affected
All

To Reproduce
run getic.sh before fixing it for issue #1155 and then resubmit job

[lgannoaa]

Job getic task successfully completed on first attempt. It is recommended only rerun the failed job as needed.
The job getic.sh should be updated with exception handlining in place to fail the job if the target directory is not empty.
Will provide a PR for the fix.