Ensure assertion matches dict iter order in test

Ensure assertion matches dict iter order in test

Fixes a test_linux_ip_lib test that made an assertion
on a command that was called that could fail depending
on the order of the dictionary when it was iterated over.

This patch makes the assertion match the order that the
command is constructed by iterating through the dictionary
as well.

Partial-Bug: #1348818
Change-Id: I7baa518169c193f7e98d38632e1db16eb57ffee7