not using wave offset, remove it

vacation.p8

@@ -1431,14 +1431,8 @@ function setup_arcade_pal()
  pal(game_uw_pal, 2)
 end
 
--- global wave amplitude clock
--- wave per 2 seconds
--- optional toff: offset. at
--- toff==0 draw directly under
--- the dolphin
-function wave(toff)
- toff = toff or 0
- return 2.5 * sin((t()+toff)>>1)
+function wave()
+ return 2.5 * sin((t())>>1)
 end
 
 function clear_alt_pal_bits()