This checks if nixpart is able to mount the filesystems from scratch again, just
with the information provided by the kickstart file.
Found an odd issue about findmnt here, because it seems to not show /mnt/boot,
even though it _is_ mounted and even shows up in /proc/self/mountinfo. I'm not
quite sure whether this is a bug or I'm doing something wrong here, but might
need some investigation.
Mountpoints are checked by adding empty canary files, remounting and checking if
the same canaries still exist. If they don't, the partitioner either has
formatted the filesystem or just not mounted the device. Either way, both
shouldn't happen, but that's why we're testing it, no? :-)
Signed-off-by: aszlig <aszlig@redmoonstudios.org>