Drop deprecated namespace for oslo.rootwrap
Drop deprecated namespace for oslo.rootwrap

The oslo team is recommending everyone to switch to the
non-namespaced versions of libraries.[1]
oslo.rootwrap suggests to use oslo_rootwrap.cmd:main.[2]

[1]https://blueprints.launchpad.net/oslo-incubator/+spec/drop-namespace-packages
[2]https://github.com/openstack/oslo.rootwrap#using

Change-Id: I1fb59b43912afb4b2f85ecade1ee1a7154c9efba

naterh/ironic,dims/ironic,pshchelo/ironic,openstack/ironic,bacaldwell/ironic,naototty/vagrant-lxc-ironic,ionutbalutoiu/ironic,bacaldwell/ironic,SauloAislan/ironic,hpproliant/ironic,openstack/ironic,NaohiroTamura/ironic,pshchelo/ironic,NaohiroTamura/ironic,redhat-openstack/ironic,ramineni/myironic,Tan0/ironic,supermari0/ironic,rdo-management/ironic,naototty/vagrant-lxc-ironic,devananda/ironic,ionutbalutoiu/ironic,SauloAislan/ironic,dims/ironic