Don't modify /sbin/init on the build host when using command `AGENT_INIT="yes" ./rootfs.sh centos` to build rootfs.
Fixes: #430
Signed-off-by: liangxianlong <liang.xianlong@zte.com.cn>
move all osbuilder files into `tools` directory to be able
to merge this into kata-containers repo.
Signed-off-by: Salvador Fuentes <salvador.fuentes@intel.com>