require_programs: Debian: find kpartx and losetup
In Debian, /usr/sbin is not in PATH of regular users unless using sudo. Fix that pmbootstrap won't find kpartx and losetup in /usr/sbin, and complains about these even though they are installed.
Fix #2489 (closed)
Fix #2482 (closed)
Fix #2492 (closed)
Edited by Oliver Smith