Fix to not use the pointer which is released. Decommission peer list contains shared pointer.
This in turn releases the memory as it is the last reference. So dont use the pointer from same.
Take the required data before releasing.
Bug# https://bugs.launchpad.net/juniperopenstack/+bug/1328843
Change-Id: I481e0496094d5b2571aa5b3855a373ae3fa05062