video: fbdev: omapfb: Remove redundant 'flush_workqueue()' calls

'destroy_workqueue()' already drains the queue before destroying it, so
there is no need to flush it explicitly.

Remove the redundant 'flush_workqueue()' calls.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/omap2/omapfb/omapfb-main.c

@@ -1854,7 +1854,6 @@ static void omapfb_free_resources(struct omapfb2_device *fbdev)
 	}
 
 	if (fbdev->auto_update_wq != NULL) {
-		flush_workqueue(fbdev->auto_update_wq);
 		destroy_workqueue(fbdev->auto_update_wq);
 		fbdev->auto_update_wq = NULL;
 	}