Added simple error message on failed mkisofs. When mkisofs failed, the script would still claim "Success".
Added simple error message on failed mkisofs.
When mkisofs failed, the script would still claim "Success".

smilart/scripts,smilart/scripts,mjg59/scripts,glevand/coreos--scripts,marineam/coreos-scripts,coreos/scripts,mjg59/scripts,marineam/coreos-scripts,coreos/scripts,smilart/scripts,glevand/coreos--scripts,mjg59/scripts,marineam/coreos-scripts