This is just an artifact of an incomplete /usr/sbin merge switch.

Please run the following commands to have a working system and with 
/usr/sbin fully merged:

- xbps-install -Suv
- if /usr/sbin is a directory and not a symlink, remove all regular files 
on it, keep the symlinks.
  - Reboot
  - runit-void will then make /usr/sbin a symlink to /usr/bin, and the old 
/usr/sbin directory will be renamed to /usr/sbin.old
- Reconfigure nvidia `xbps-reconfigure -f nvidia{,-dkms}`
- Your system should be fully functional again.

Cheers