fn remove_hotplug_bridge<V: VmArch, Vcpu: VcpuArch>(
    linux: &RunnableLinuxVm<V, Vcpu>,
    sys_allocator: &mut SystemAllocator,
    buses_to_remove: &mut Vec<u8>,
    hotplug_key: HotPlugKey,
    child_bus: u8
) -> Result<()>