radv: fence issues with vrwebhelper
From #vronlinux on IRC:
- SteamVR settings not working
- Using AMDVLK for vrwebhelper works
- Fails on 19.3/20.0
- RX 570
- Kernel 5.5 (and 5.4 as well)
- Half Life : Alyx fails as well with a timout-out regarding Mongoose
- No other VR games seem affected.