vhost-scsi: log event queue write descriptors

vhost-scsi: log event queue write descriptors

Log write descriptors for the event queue, leveraging vhost_get_vq_desc()
to retrieve the array of write descriptors to obtain the log buffer.

There is only one path for event queue.

Suggested-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20250403063028.16045-9-dongli.zhang@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>