nvme firmware log page should maybe have more than zeros

[rmustacc]

While taking the illumos nvme tests for a spin on Propolis one thing it tripped over was the fact that the firmware log page was basically all zeros. This is obviously very low priority, but firmware slot 0 is not a valid firmware slot id. This is super low priority, but one should consider:

• Indicating that the current firmware slot is slot 1.
• Faking up some version string.