drain: return on first error
drain: return on first error

If one error is encountered it is unlikely any further attempts will
succeed, so fail fast.

nak3/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,hashicorp/nomad,dvusboy/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,dvusboy/nomad,hashicorp/nomad,hashicorp/nomad,burdandrei/nomad,nak3/nomad,nak3/nomad,nak3/nomad,dvusboy/nomad,hashicorp/nomad,burdandrei/nomad,nak3/nomad,nak3/nomad,burdandrei/nomad,dvusboy/nomad,dvusboy/nomad,burdandrei/nomad,burdandrei/nomad,nak3/nomad