netfilter: xt_qtaguid: Allow tracking loopback

In the past it would always ignore interfaces with loopback addresses.
Now we just treat them like any other.
This also helps with writing tests that check for the presence
of the qtaguid module.

Signed-off-by: JP Abgrall <jpa@google.com>
Merge remote-tracking branch 'common/android-3.0' into android-omap-3.0

* common/android-3.0:
  netfilter: xt_qtaguid: Allow tracking loopback
Merge branch 'android-omap-3.0' into cm-10.1