In virsh we have two printing functions: vshPrint() which prints a
string onto stdout and vshPrintExtra() which does not print anything
if virsh is run in quiet mode. Usually, the former is used to print
actual results, while the latter to print strings like table headers
and other formatting stuff. However, in cmdDomIfAddr we have
mistakenly used vshPrintExtra even for actual data. After this patch,
the output should look like the following: