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/cpu_buffer.c

@@ -111,14 +111,18 @@ void start_cpu_work(void)
 
 void end_cpu_work(void)
 {
-	int i;
-
 	work_enabled = 0;
+}
+
+void flush_cpu_work(void)
+{
+	int i;
 
 	for_each_online_cpu(i) {
 		struct oprofile_cpu_buffer *b = &per_cpu(op_cpu_buffer, i);
 
-		cancel_delayed_work(&b->work);
+		/* these works are per-cpu, no need for flush_sync */
+		flush_delayed_work(&b->work);
 	}
 }