tools/disktool: Fix progress bar when exporting large parcels
tools/disktool: Fix progress bar when exporting large parcels

- Fix missing/wrong progress bar when exporting parcels > 4 GB
(introduced in 2f8641b6)

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr