p_floor: EV_DoFloor floor_raiseFloor24 contains dead assignment using offset_from

[sunsided]

Context

EV_DoFloor in room/src/doom/p_floor.rs, floor_raiseFloor24 arm.

Problem

The arm contains a dead assignment that uses offset_from with the wrong operand type:

(*floor).floordestheight =
    (*floor).sector.offset_from(sec as *mut sector_t) as fixed_t;
(*floor).floordestheight = (*sec).floorheight + 24 * FRACUNIT;

The first line computes a pointer offset (in sector_t strides) and stores it as a fixed_t, which is meaningless. It is immediately overwritten by the second line, so the assignment is harmless but misleading.

Location

room/src/doom/p_floor.rs:449 (flagged with // FIXME:).

Suggested fix

Delete the dead first assignment.