We don't (and shouldn't) copy /tmp to the final image.
Also fix the service file permissions - it is not executable.
Change-Id: I75e09662a63768627f8123a7fe7f5d9ca2d942c5
Apparently, DIB is sensitive to file names, at least the package-install
feature. Let us make sure we use ironic-python-agent-ramdisk, not ironic-agent.
Change-Id: I929c0652c320734ff82dd257180c4b7bd156c478