Cleanup: Remove unnecessary VehicleRandomBits()

Simple Random() assignment to byte does the same.

src/ship_cmd.cpp

@@ -905,7 +905,7 @@ CommandCost CmdBuildShip(DoCommandFlag flags, TileIndex tile, const Engine *e, V
 		v->date_of_last_service = TimerGameCalendar::date;
 		v->build_year = TimerGameCalendar::year;
 		v->sprite_cache.sprite_seq.Set(SPR_IMG_QUERY);
-		v->random_bits = VehicleRandomBits();
+		v->random_bits = Random();
 
 		v->UpdateCache();