Well, you're right that you installed it, but that's the wrong way to update games for loadiine. Next time, follow the directions people give you instead of going and doing your own thing when you obviously don't know what you're doing. Even more so when you're the one who made a thread about it, only to ignore half the answers you were given.
Try actually following the advice given to you by TreyTrent. We don't reply for our health (well, some of us might hehe).
Extract the update (.app files), copy code and content folder to your Mario Kart 8 game folder on SD card.
if your game is at wiiu/games/MK8 (replace MK8 with any game that has an update), copy the extracted folders like so. Overwrite existing files and folders.
<extracted_update_folder>/code --> wiiu/games/MK8
<extracted_update_folder>/content --> wiiu/games/MK8
<extracted_update_folder>/meta --> wii/games/MK8