oprofile: Remove deprecated use of flush_scheduled_work()

flush_scheduled_work() is deprecated and scheduled to be removed.
sync_stop() currently cancels cpu_buffer works inside buffer_mutex and
flushes the system workqueue outside.  Instead, split end_cpu_work()
into two parts - stopping further work enqueues and flushing works -
and do the former inside buffer_mutex and latter outside.

For stable kernels v2.6.35.y and v2.6.36.y.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Robert Richter <robert.richter@amd.com>

drivers/oprofile/buffer_sync.c

@@ -190,7 +190,7 @@ void sync_stop(void)
 	profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
 	task_handoff_unregister(&task_free_nb);
 	mutex_unlock(&buffer_mutex);
-	flush_scheduled_work();
+	flush_cpu_work();
 
 	/* make sure we don't leak task structs */
 	process_task_mortuary();