Fix race in iomux-link
Fix race in iomux-link

Wait until all connections are broken instead of the first connection.

Change-Id: Ic09c32deb0338eabf58cae98af01bd7f7e0bd2c3

tsaleh/garden,tangfeixiong/garden,tangfeixiong/garden,cloudfoundry-incubator/garden,cloudfoundry-incubator/garden-linux,savaki/garden,cloudfoundry-incubator/garden-linux,tsaleh/garden,cloudfoundry-incubator/garden-linux,shashidharatd/garden-linux,cloudfoundry-incubator/garden,shashidharatd/garden-linux,savaki/garden,shashidharatd/garden-linux,shashidharatd/garden-linux