virtio_block device ordering reversed

[kallisti5]

Just noticed this in qemu...

qemu-system-x86_64 -machine pc -chardev socket,id=console,path=/var/tmp/qemu-1354524-console.sock,server,nowait -serial chardev:console -nodefaults -m 4G -cpu max -netdev user,id=vnet,hostfwd=:127.0.0.1:0-:22 -device virtio-net-pci,netdev=vnet -smp 8 -enable-kvm -drive file=/tmp/haiku.img,if=none,id=drive0,cache=writeback -device virtio-blk,drive=drive0,bootindex=0 -drive file=/tmp/vm-test-i3tff3zn.tmp/data-fa2df.tar,if=none,id=data-fa2df,cache=writeback,format=raw -device virtio-blk,drive=data-fa2df,serial=data-fa2df,bootindex=1 -device VGA}}}

In the example above:
* -drive file=/tmp/haiku.img,if=none,id=drive0,cache=writeback
  * -device virtio-blk,drive=drive0,bootindex=0
* -drive file=/tmp/vm-test-i3tff3zn.tmp/data-fa2df.tar,if=none,id=data-fa2df,cache=writeback,format=raw
  * -device virtio-blk,drive=data-fa2df,serial=data-fa2df,bootindex=1 

These are positioned as:
* drive0 = haiku.img
* drive1 = data-fa2df.tar

However, after booting into qemu:
* Haiku is /dev/disk/virtual/virtio_block/1/raw
* tar is /dev/disk/virtual/virtio_block/0/raw

The attachment ordering is reversed (or random? Though the reverse seems consistent)

[korli]

the ordering actually is from the device manager. ​https://review.haiku-os.org/c/haiku/+/5393

[waddlesplash]

Fix merged in hrev56206.