cgroup/cpuset: Remove stale text

/*

 * There are two global locks guarding cpuset structures - cpuset_mutex and

 * callback_lock. We also require taking task_lock() when dereferencing a

 * task's cpuset pointer. See "The task_lock() exception", at the end of this

 * comment.  The cpuset code uses only cpuset_mutex. Other kernel subsystems

 * can use cpuset_lock()/cpuset_unlock() to prevent change to cpuset

 * callback_lock. The cpuset code uses only cpuset_mutex. Other kernel

 * subsystems can use cpuset_lock()/cpuset_unlock() to prevent change to cpuset

 * structures. Note that cpuset_mutex needs to be a mutex as it is used in

 * paths that rely on priority inheritance (e.g. scheduler - on RT) for

 * correctness.

 * The cpuset_common_seq_show() handlers only hold callback_lock across

 * small pieces of code, such as when reading out possibly multi-word

 * cpumasks and nodemasks.

 *

 * Accessing a task's cpuset should be done in accordance with the

 * guidelines for accessing subsystem state in kernel/cgroup.c

 */

static DEFINE_MUTEX(cpuset_mutex);