apt: do not consider not-removed and not-upgraded packages as changes.

If one pins a package and does a 'apt-get dist-upgrade' then the
output looks like:

    # apt-get dist-upgrade
    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    Calculating upgrade... Done
    The following packages have been kept back:
      cassandra
    0 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.

The check for any changes made should only be on the 'upgraded' and
'newly installed' values and not include the 'to remove' and 'not
upgraded' values.