Create empty file by using os.mknod
Create empty file by using os.mknod

it is more safe and pythonic.

Change-Id: I728649af37cee8d1e255bb0a389cbc532e551c74

openstack/kolla,dardelean/kolla-ansible,tonyli71/kolla,mandre/kolla,mrangana/kolla,mrangana/kolla,nihilifer/kolla,mandre/kolla,toby82/kolla,tonyli71/kolla,toby82/kolla,openstack/kolla,rahulunair/kolla,intel-onp/kolla,dardelean/kolla-ansible,GalenMa/kolla,negronjl/kolla,mandre/kolla,dardelean/kolla-ansible,limamauricio/mykolla,stackforge/kolla,coolsvap/kolla,stackforge/kolla,GalenMa/kolla,negronjl/kolla,coolsvap/kolla,rahulunair/kolla,coolsvap/kolla,limamauricio/mykolla,limamauricio/mykolla,nihilifer/kolla,toby82/kolla,negronjl/kolla,intel-onp/kolla,stackforge/kolla