nvme-print-json: display only verbose output

Having separate regular & verbose outputs makes more sense for the
stdout outputs, and not necessarily for the JSON outputs. So let's
make things simpler by having the JSON output everything, and
nothing short.

Suggested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Martin George <marting@netapp.com>

Author: martin-gpy