AJCOPSSM-25 Fix session port unit tests.

2 bugs were combining to make testSetPortWrongPort() pass when it shouldn't
have been:

- The setPortSetUp() helper method was always setting the PGM and the
  independent bus attachment to the same session port. This defeated the
  intent of testSetPortWrongPort(), which is to set them to different ports
  and verify that they could not communicate.

- The testSetPortWithTwoGroups() was not calling the cleanup helper method
  setPortCleanUp() at the end of its test, and it was executing before
  testSetPortWrongPort() (even though it appears later in the source file).