vdev_queue:
- Track the last position of each vdev, including the io size,
in order to detect linear access of the following zio.
- Remove duplicate `vq_lastoffset`
vdev_mirror:
- Correctly calculate the zio offset (signedness issue)
- Deprecate `vdev_queue_register_lastoffset()`
- Add `VDEV_LABEL_START_SIZE` to zio offset of leaf vdevs
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Gvozden Neskovic <neskovic@gmail.com>
Closes #6461