fdc-test: Test state for existing cases more thoroughly

This just adds a few additional checks of the MSR and interrupt pin to
the already existing test cases.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Message-id: 1432214378-31891-9-git-send-email-kwolf@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
