541a9a0 bumblebee: Fix nvidia-fallback instruction

Authored and Committed by egeretto 5 years ago
    bumblebee: Fix nvidia-fallback instruction
    
    When using the Nvidia proprietary driver from `rpmfusion-nonfree-nvidia-driver`, the `nvidia-fallback` service is disabled by default but it is started as a dependency. The correct way to prevent it from starting is to mask it.