* Stamp the commit lsn into each item if necessary.
* Free descriptors pointing to items which are not dirty if freeing_chunk
* is zero. If freeing_chunk is non-zero, then we need to unlock all
* Stamp the commit lsn into each item if necessary.
* Free descriptors pointing to items which are not dirty if freeing_chunk
* is zero. If freeing_chunk is non-zero, then we need to unlock all