cgroup: cgroup-v1: clean up kernel-doc notation

Fix kernel-doc warnings found in cgroup-v1.c:

kernel/cgroup/cgroup-v1.c:55: warning: No description found for return value of 'cgroup_attach_task_all'
kernel/cgroup/cgroup-v1.c:94: warning: expecting prototype for cgroup_trasnsfer_tasks(). Prototype was for cgroup_transfer_tasks() instead
cgroup-v1.c:96: warning: No description found for return value of 'cgroup_transfer_tasks'
kernel/cgroup/cgroup-v1.c:687: warning: No description found for return value of 'cgroupstats_build'
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: cgroups@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>

kernel/cgroup/cgroup-v1.c

@@ -50,6 +50,8 @@ bool cgroup1_ssid_disabled(int ssid)
  * cgroup_attach_task_all - attach task 'tsk' to all cgroups of task 'from'
  * @from: attach to all cgroups of a given task
  * @tsk: the task to be attached
+ *
+ * Return: %0 on success or a negative errno code on failure
  */
 int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
 {
@@ -80,7 +82,7 @@ int cgroup_attach_task_all(struct task_struct *from, struct task_struct *tsk)
 EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
 
 /**
- * cgroup_trasnsfer_tasks - move tasks from one cgroup to another
+ * cgroup_transfer_tasks - move tasks from one cgroup to another
  * @to: cgroup to which the tasks will be moved
  * @from: cgroup in which the tasks currently reside
  *
@@ -89,6 +91,8 @@ EXPORT_SYMBOL_GPL(cgroup_attach_task_all);
  * is guaranteed to be either visible in the source cgroup after the
  * parent's migration is complete or put into the target cgroup.  No task
  * can slip out of migration through forking.
+ *
+ * Return: %0 on success or a negative errno code on failure
  */
 int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from)
 {
@@ -682,6 +686,8 @@ int proc_cgroupstats_show(struct seq_file *m, void *v)
  *
  * Build and fill cgroupstats so that taskstats can export it to user
  * space.
+ *
+ * Return: %0 on success or a negative errno code on failure
  */
 int cgroupstats_build(struct cgroupstats *stats, struct dentry *dentry)
 {