if.sh on newer SmartOS kernel returns empty data

[sax]

In a non-global SmartOS zone, the if.sh check returns no data.

Assuming an interface net0, it appears to run the following command:

> /usr/bin/kstat -p -m z14_net0

The working command to collect this data (on platform image joyent_20131105T084235Z) would be:

> kstat -p -n net0

[sax]

@neophenix Just wanted to make sure you saw this. I hesitate to fix this myself, as I don't know what other variations there are. Don't want to accidentally break things for OmniOS, or write too-complicated code if there are alternatives.

[neophenix]

It looks like the issue is that the latest SmartOS removed all but the physical layer stats, which isn't what if.sh returns on other platforms, so we might just need a new script here.