Fix harcoded interface for ip show commnad

fix harcoded interface for ip show command
in test delete vip.

Change-Id: Ia67e5464937af05fdf6cedf40652004b0edb1e2a
Closes-Bug: #1320146
(cherry picked from commit fc4c85a72061cedea564baad9353e9b79fc566fe)
Merge "Fix harcoded interface for ip show commnad" into stable/4.1