Module object allocation size overflow corrupts the manager object pool

A ThreadX module chooses `object_size` when it calls `txm_module_object_allocate`. The Module Manager adds its own 16-byte private header to that size and asked the object pool for the result **without checking the addition**. A size near the top of a `ULONG` wrapped, the pool served a block far smaller than the header, and the manager then wrote the header past the end of it and into the neighbouring byte-pool block.