Baremetal deploy make_bm_hosts step fails when baremetal-operator repo is not present

The deploy/metal3/scripts/01_metal3.sh script expects /root/go/src/github.com/metal3-io/baremetal-operator/cmd/make-bm-worker/main.go to be present before executing.  When it is absent, the step fails.

Note that the VM deploy does not have this issue, it clones the repo as needed.