I have rooted my Huawei P8-Lite ALE-L21 with superuser.zip. After successful root I tried to change superuser app. So, I have installed KingoUser.apk and after that I have clicked on superSu app -> settings -> switch superuser app. It didn't work. So, I installed Link2SD app and converted KingoUser as a system app. Now, when I launching SuperSu or KingoUser, some warning message pops up and says that the su binary needs to be updated.
There is no way to flash my phone cause Huawei haven't released my build version as a stand-alone flash file.
How can I unroot my phone now ?