Actually encode the SolidFire json dump result

The SolidFire driver intends to do a encode on the json data to utf-8,
unfortunatly it's not really doing anything because the syntax of the
calls is wrong.

This patch changes things to actually perform the encoding.

Change-Id: I2bc94ed1fdc1dd5f9a6371ae5f63a955f213bc15
Closes-Bug: #1355622
Merge "Actually encode the SolidFire json dump result"