/proc/sys/kernel/cap_last_cap. This is needed to determine the highest valid
 capability of the running kernel. Reference:
 https://lkml.org/lkml/2011/10/15/42
Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/apparmor/+bug/1378977Acked-By: Jamie Strandboge <jamie@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>