You can just restore the image in the app and flash it to the other slot:
Ok, so none of your slots failed, that’s something. Please check the version in recovery as well, so we are sure you are actually running A.170 
You can just restore the image in the app and flash it to the other slot:
Ok, so none of your slots failed, that’s something. Please check the version in recovery as well, so we are sure you are actually running A.170