snapshot_disk: Fix cfg file to list negative test options

It seems listing more than one "only" filter in the negative_test resulted
in none of the tests being listed as negative.  I found that if I added
all the "no" options from the positive_test on the same line that would
list the 19 negative_test options.
Merge pull request #124 from jferlan/snapshot_disk

snapshot_disk: Fix cfg file to list negative test options