The chown command '-p' is invalid as below:
stack@ubuntu:~$ sudo chown -R ironic -p /tftpboot
chown: invalid option -- 'p'
Try 'chown --help' for more information.
The '-p' must be a typo of '-P'. But the manual says
'-P' option is default. So '-p' has been removed.
-P do not traverse any symbolic links (default)
Change-Id: Ic012a6a991645a128389367f07c9709366a09822
5fd47bd095