Suggest warning added to --resume-job not to use loop file as argument

[tomachinz]

Believe it or not, I was foolish enough to using the loop file as argument to rsremap --resume-job and maybe blasted my (previously XFS) home folder to ashes. Ah well. Should have been slightly more careful. Suggest feature to add prominence to the warning:

The loop file created by fstransform must NEVER be as argument to 'fsremap --resume-job= {...}'. You would IRREVERSIBLY LOSE YOUR DATA!
Maybe this could be raised in the readme.txt file?

/usr/sbin/fsremap -q --questions=yes --cmd-umount=/usr/bin/umount -- /dev/sda4  /media/zorin/0fc42a38-4019-402b-ac5e-cc1eadd82d27/.fstransform.loop.20056
setting log level to NOTICE
fsremap: starting job 5, persistence data and logs are in '/var/tmp/fstransform/fsremap.job.5'
if this job is interrupted, for example by a power failure,
you CAN RESUME it with: /usr/sbin/fsremap -q --resume-job=5 -- /dev/sda4
ERROR: loop-file '/media/zorin/0fc42a38-4019-402b-ac5e-cc1eadd82d27/.fstransform.loop.20056' can be opened read-write, it means device '/dev/sda4' is not mounted read-only as it should
root@zorin:/home/zorin#