Match zpool output for omnios 151006

### Version:
7.0.4

### Environment: [Details about the environment such as the Operating System, cookbook details, etc...]
OmniOS 151006 LTS

### Scenario:
Ohai doesn't correctly report zpool information.  This is a result of OmniOS not reporting a numeric value for the zpool version.  This causes the regular expression that ohai uses to fail.



### Steps to Reproduce:
Run ohai on OmniOS 151006.  I am using the LTS branch so I don't know if this is still an issue on the latest stable branch.


### Expected Result:

 "zpools": {
    "rpool": {
      "pool_size": "111G",
      "pool_allocated": "66.3G",
      "pool_free": "44.7G",
      "capacity_used": "59%",
      "dedup_factor": "1.00x",
      "health": "ONLINE",
      "zpool_version": "-",
      "devices": {
        "c4t4d0s0": {
          "state": "ONLINE",
          "errors": {
            "read": "0",
            "write": "0",
            "checksum": "0"
          }
        },
        "c4t5d0s0": {
          "state": "ONLINE",
          "errors": {
            "read": "0",
            "write": "0",
            "checksum": "0"
          }
        }
      }
    }
}

### Actual Result:
zpools: {
}