Move storage_address discovery into a single task
Move storage_address discovery into a single task

The storage address variable needs to be defined before running other
common tasks. The `storage_address` variable, when defined in a cinder
storage backend, causes an exception at runtime as the host_var will be
undefined. This patch moves the `storage_address` discovery set of tasks
into its one task and allows the option to be known before running
anything else.

Closes-Bug: #1632393
Change-Id: I547c72943396af92df2a298470e3f89b4d1e3a2d
Signed-off-by: Kevin Carter <ffb54fded2f22052678e45d78b58d223654eb6fa@rackspace.com>

bunchc/openstack-ansible,weezer/openstack-ansible,openstack/openstack-ansible,os-cloud/os-ansible-deployment,cfarquhar/openstack-ansible,cloudnull/os-ansible-deployment,bunchc/openstack-ansible,BjoernT/os-ansible-deployment,Logan2211/openstack-ansible,cfarquhar/openstack-ansible,robb-romans/openstack-ansible,openstack/openstack-ansible,weezer/openstack-ansible,BjoernT/openstack-ansible,BjoernT/os-ansible-deployment,stackforge/os-ansible-deployment,BjoernT/openstack-ansible,yanyao/openstack-ansible,Logan2211/openstack-ansible,BjoernT/os-ansible-deployment,robb-romans/openstack-ansible,stackforge/os-ansible-deployment,yanyao/openstack-ansible,os-cloud/os-ansible-deployment,cloudnull/os-ansible-deployment