fbdev: uvesafb: Call cn_del_callback() at the end of uvesafb_exit()

Delete the v86d netlink only after all the VBE tasks have been
completed.

Fixes initial state restore on module unload:
uvesafb: VBE state restore call failed (eax=0x4f04, err=-19)

Signed-off-by: Jorge Maidana <jorgem.linux@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/uvesafb.c

@@ -1928,10 +1928,10 @@ static void uvesafb_exit(void)
 		}
 	}
 
-	cn_del_callback(&uvesafb_cn_id);
 	driver_remove_file(&uvesafb_driver.driver, &driver_attr_v86d);
 	platform_device_unregister(uvesafb_device);
 	platform_driver_unregister(&uvesafb_driver);
+	cn_del_callback(&uvesafb_cn_id);
 }
 
 module_exit(uvesafb_exit);