Revert "Fix cpu timers exit deadlock and races"

	if (unlikely(p == NULL))

		return 0;

	spin_lock(&p->sighand->siglock);

	if (!list_empty(&timer->it.cpu.entry)) {

		read_lock(&tasklist_lock);

		if (unlikely(p->signal == NULL)) {

			/*

		 * Take us off the task's timer list.  We don't need to

		 * take tasklist_lock and check for the task being reaped.

		 * If it was reaped, it already called posix_cpu_timers_exit

		 * and posix_cpu_timers_exit_group to clear all the timers

		 * that pointed to it.

			 * We raced with the reaping of the task.

			 * The deletion should have cleared us off the list.

			 */

			BUG_ON(!list_empty(&timer->it.cpu.entry));

		} else {

			/*

			 * Take us off the task's timer list.

			 */

			spin_lock(&p->sighand->siglock);

			list_del(&timer->it.cpu.entry);

		put_task_struct(p);

	}

			spin_unlock(&p->sighand->siglock);

		}

		read_unlock(&tasklist_lock);

	}

	put_task_struct(p);

	return 0;

}