(FACT-546) Enclose interface name in single quotes

[vinzent]

oVirt/RHEV creates a ";vdsmdummy;" network interface.

facter outputs many messages:
sh: vdsmdummy: command not found

ifconfig and ip command lines are called like "/sbin/ifconfig ;vdsmdummy;" which is interpreted as "ifconfig" and "vdsmdummy" (same for the ip command).

The interface names should be enclosed by single quotes.

[puppetcla]

CLA signed by all contributors.

[whopper]

@vinzent thanks for the contribution!

We'll be having our weekly pull request triage this Wednesday, so we'll discuss getting this merged in then. Using single quotes with ifconfig and ip worked on every platform that I tested, so 👍 from me.

[kylog]

@whopper do you know if cfacter has any prob with interface names with semi-colons?

[whopper]

@kylog I'm not sure - I'll go poke around and see if I can replicate this.

[whopper]

@kylog it looks like cfacter is unaffected since it uses the getifaddrs() function to grab interface info directly rather than having to shell out to ifconfig or ip. So, I believe we should be good on that front!