make fio scripts python3-ready (part 2)

make fio scripts python3-ready (part 2)

NOTE: this patch (part 2) is in addition to commit 5eac3b00238b
(this patch was missed on that submit/commit (part 1)).

Many distributions are moving to python3 by default.  This is
another patch to make the python scripts in fio python3-ready.

Conversion was facilitated with automated tools.

The modified scripts pass rudimentary testing when run under
python2.7 as well as python3.

Signed-off-by: Bill O'Donnell <billodo@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>