Ensure parameter order of assertEqual correct

As part of patch a2c3e9d7d8a25300cc3586c1267f545a3434f232 it
was identified that the parameter order to assertEqual in
test_{port,chassis,node}.py was often not following what is
considered standard practice and inconsistently applied.
This patch updates all instances to follow the same approach.

Change-Id: Ied28371d5152bbd3ebd2bb8353f72ed82ddd6861
Merge "Ensure parameter order of assertEqual correct"