Storage add_node/setup fails

Closes-Bug: #1397820
Issue: 1. Add storage node does not invoke setup_storage.
       2. Setup storage fails as there are 2 ips for the same
          interface.
Fix: 1. Add storage node does not pass storage setup mode.
        This caused the setup storage to be run with mode as 'None'
        Fixed it by passing the correct mode.
     2. Two interfaces somehow got the same ip address. This caused
        Setup storage to fail. Fixed it by taking the head entry.
Test: Verified in QA setup.

Change-Id: Icbdf1653b7f839a667f1ede2f755826ba570d1a8