interruptible_wait: check for interruption immediately
interruptible_wait: check for interruption immediately

Akin to 651274e5081b27f3c4b82804721d0661bf863c61

makunterry/packer-builder-xenserver,fr34k8/packer-builder-xenserver,xenserverarmy/packer,dongyuzheng/packer-builder-xenserver,june07/packer-builder-xenserver,rdobson/packer-builder-xenserver,june07/packer-builder-xenserver,simonfuhrer/packer-builder-xenserver-1,fr34k8/packer-builder-xenserver,makunterry/packer-builder-xenserver,dongyuzheng/packer-builder-xenserver,rdobson/packer-builder-xenserver,conceptboard/packer,conceptboard/packer,simonfuhrer/packer-builder-xenserver-1,xenserverarmy/packer