libifconfig_get_description(): Confusing code

Investigate if the following section of code is necessary:

```
} else if (ifr.ifr_buffer.length > descrlen) {
    descrlen = ifr.ifr_buffer.length;
    continue;
}
```

I _think_ this tells the next ioctl() call to allocate a larger buffer for the name, but this needs digging into how the SIOCGIFDESCR ioctl() call is implemented.
