Uninstall cuda 9.1 and install cuda 8.0

sudo apt-get --purge remove 'cuda*' # remove all the cuda
sudo apt-get autoremove --purge cuda
sudo dpkg -i ./cuda-repo-ubuntu1604-8-0-local-ga2_8.0.61-1_amd64.deb 
sudo apt-get update
sudo apt-get install cuda-8.0