Fix cancel_preparation call in case of failure
Fix cancel_preparation call in case of failure

It should be _failed if the timer runs out, not _done. Only difference
is a log entry though, so not that big of a deal.

foosel/OctoPrint,foosel/OctoPrint,foosel/OctoPrint,Jaesin/OctoPrint,Jaesin/OctoPrint,foosel/OctoPrint,Jaesin/OctoPrint,Jaesin/OctoPrint