LSM: fix documentation for the task_setscheduler hook

The task_setscheduler hook was changed in the commit
"security: remove unused parameter from security_task_setscheduler()"
(b0ae1981). The arguments @policy, @lp were removed from the hook.
This patch updates the documentation accordingly.
Signed-off-by: Denis Efremov <efremov@ispras.ru>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

include/linux/lsm_hooks.h

@@ -671,10 +671,8 @@
  *	Return 0 if permission is granted.
  * @task_setscheduler:
  *	Check permission before setting scheduling policy and/or parameters of
- *	process @p based on @policy and @lp.
+ *	process @p.
  *	@p contains the task_struct for process.
- *	@policy contains the scheduling policy.
- *	@lp contains the scheduling parameters.
  *	Return 0 if permission is granted.
  * @task_getscheduler:
  *	Check permission before obtaining scheduling information for process