Makefile: remove unused golang.org/x/tools/cmd/stringer dep
Makefile: remove unused golang.org/x/tools/cmd/stringer dep

pecigonzalo/packer,rnaveiras/packer,grubernaut/packer,ricardclau/packer,dave2/packer,dave2/packer,timsutton/packer,mitchellh/packer,grubernaut/packer,bryson/packer,paulmey/packer,rnaveiras/packer,dave2/packer,ricardclau/packer,ricardclau/packer,mitchellh/packer,bryson/packer,hashicorp/packer,mitchellh/packer,pecigonzalo/packer,dave2/packer,pecigonzalo/packer,paulmey/packer,timsutton/packer,pecigonzalo/packer,timsutton/packer,tas50/packer,paulmey/packer,grubernaut/packer,bryson/packer,hashicorp/packer,grubernaut/packer,ricardclau/packer,tas50/packer,paulmey/packer,rnaveiras/packer,bryson/packer,rnaveiras/packer,dave2/packer,rnaveiras/packer,rnaveiras/packer,tas50/packer,grubernaut/packer,paulmey/packer,bryson/packer,grubernaut/packer,dave2/packer,hashicorp/packer,tas50/packer,bryson/packer,mitchellh/packer,tas50/packer,paulmey/packer,ricardclau/packer,timsutton/packer,mitchellh/packer,hashicorp/packer,ricardclau/packer,timsutton/packer,tas50/packer,timsutton/packer