video: don't use flush_scheduled_work() in fb_defio

flush_scheduled_work() in on the way out.  fb_deferred_io_cleanup()
can simply sync-cancel info->deferred_work instead of cancel +
flush_scheduled_work().  Drop flush_scheduled_work() usage.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jaya Kumar <jayalk@intworks.biz>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/video/fb_defio.c

@@ -216,8 +216,7 @@ void fb_deferred_io_cleanup(struct fb_info *info)
 	int i;
 
 	BUG_ON(!fbdefio);
-	cancel_delayed_work(&info->deferred_work);
-	flush_scheduled_work();
+	cancel_delayed_work_sync(&info->deferred_work);
 
 	/* clear out the mapping that we setup */
 	for (i = 0 ; i < info->fix.smem_len; i += PAGE_SIZE) {