CA-68010: unplug and destroy qemu blkfront VBDs before guest VBDs. This means we won't leak a qemu frontend VBD if the storage backend fails.
CA-68010: unplug and destroy qemu blkfront VBDs before guest VBDs. This means we won't leak a qemu frontend VBD if the storage backend fails.

Signed-off-by: David Scott <63c9eb0ea83039690fefa11afe17873ba8278a56@eu.citrix.com>

sharady/xcp-networkd,sharady/xcp-networkd,djs55/xcp-networkd,johnelse/xcp-rrdd,djs55/xcp-rrdd,djs55/xcp-networkd,robhoes/squeezed,koushikcgit/xcp-rrdd,koushikcgit/xcp-rrdd,johnelse/xcp-rrdd,simonjbeaumont/xcp-rrdd,koushikcgit/xcp-networkd,koushikcgit/xcp-rrdd,djs55/squeezed,koushikcgit/xcp-networkd,djs55/xcp-rrdd,simonjbeaumont/xcp-rrdd