Various fixes in this update, the full list is:
> qemu-bootlist: Take the "-boot strict=off" setting properly into account
> virtio-scsi: initialize vring avail queue buffers
> virtio: Remove global variables in block and 9p driver
> Remove superfluous checkpoints in tree.fs
> Provide "write" function in the disk-label package
> virtio: Implement block write support
> scsi: Add SCSI block write support
> deblocker: Add a 'write' function
> virtio-scsi: Fix descriptor order for SCSI WRITE commands
> board-qemu: Add a possibility to use hvterm input instead of USB keyboard
> Do not try to use virtio-gpu in VGA mode
> virtio: Fix stack comment of virtio-blk-read
> envvar: Do not read default values for /options from the NVRAM anymore
> envvar: Set properties in /options during "(set-defaults)"
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>