iotop bug #644616 needs to be fixed in stable because the elevant change
in Linux has been added to the 2.6.32 longterm tree, which the Debian
Linux kernel team intends to add to the next Debian stable point
release. The change in Linux addresses a security issue (CVE-2011-2494)
by removing access to the taskstats interface for non-root users.
Unfortunately iotop relies on this file and therefore it can only run as
root. With the debdiff below iotop will output a friendly message
instead of crashing with a Python traceback.