cgroup/cpuset: Remove stale text

Task's cpuset pointer was removed by
commit 8793d85 ("Task Control Groups: make cpusets a client of cgroups")

Paragraph "The task_lock() exception ...." was removed by
commit 2df167a ("cgroups: update comments in cpuset.c")

Remove stale text:

 We also require taking task_lock() when dereferencing a
 task's cpuset pointer. See "The task_lock() exception", at the end of this
 comment.

 Accessing a task's cpuset should be done in accordance with the
 guidelines for accessing subsystem state in kernel/cgroup.c

and reformat.

Co-developed-by: Michal Koutný <mkoutny@suse.com>
Co-developed-by: Waiman Long <longman@redhat.com>
Signed-off-by: Costa Shulyupin <costa.shul@redhat.com>
Acked-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: makelinux

kernel/cgroup/cpuset.c

@@ -197,10 +197,8 @@ static struct cpuset top_cpuset = {
 
 /*
  * 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.
@@ -229,9 +227,6 @@ static struct cpuset top_cpuset = {
  * 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);