fix: allow warping players/peds to passenger seats on towed train carriages (#3025)

[MohabCodeX]

The actual logic change is only replacing the check with an early return for seat 0. The rest of the diff is just indentation cleanup

Fixes #3025

Test Plan

Run the following commands via runcode:

1. Spawn a train engine and attach a passenger carriage:
   run train = Vehicle(538, 0, 0, 4) carriage = Vehicle(570, 0, 0, 4) attachTrailerToVehicle(train, carriage)

2. Warp into passenger seat 1 of the towed carriage:
   run warpPedIntoVehicle(me, carriage, 1)
   Expected result: Returns true and the player is warped inside the carriage seat.

3. Verify driver seat (seat 0) on the towed carriage is disallowed:
   run warpPedIntoVehicle(me, carriage, 0)
   Expected result: Returns false.