fbcon: convert last two unregister_con_driver call to do_unregister_con_driver

There are only two place use unregister_con_driver now, this patch
convert them to do_unregister_con_driver too, then we can delete
unregister_con_driver whos function can be achieved with do_unregister_con_driver
easily to reduce code size and duplication.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/video/console/fbcon.c b/drivers/video/console/fbcon.c
index e05fa83..a09c667 100644
--- a/drivers/video/console/fbcon.c
+++ b/drivers/video/console/fbcon.c
@@ -3621,8 +3621,8 @@
 	fbcon_deinit_device();
 	device_destroy(fb_class, MKDEV(0, 0));
 	fbcon_exit();
+	do_unregister_con_driver(&fb_con);
 	console_unlock();
-	unregister_con_driver(&fb_con);
 }	
 
 module_exit(fb_console_exit);