health: Fixing logging directory for storage

It shall be saved in storage- not in network-
cardiff: Avoid static definition of benchmarks

Cardiff was considering only sd<x> devices while hda or vda could exist.
The list of possible benchmarks was also harcoded which is a limitation.

This patch allow any kind of logical disk name but also detect
dynamically the test which were run.
cardiff: Adding storage support for DAHC

When calling the rampup mode for storage, let's have a good header for
this job.