World of Diving: Better fix for distortion on scuba-scooter for multiplayer

- Unadjusting the distortion works ok for 1st person, but not for 3rd
  person view (multiplayer). Fix the vertex shader properly.

- The pixel shader had accidentally been fixed as a light shader. It
  made no difference and wouldn't work properly anyway due to accessing
  components of v0 that were masked out in the declarations. Remove this.