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.

Change-Id: Ib54f7fcfa94e9913ab926ea78b4a99b78cb3b7b1
Signed-off-by: JP Abgrall <jpa@google.com>
Git-commit: af4d7c85bc8629c63360d5729cba0754b62c4345
Git-repo: https://android.googlesource.com/kernel/common/


Signed-off-by: Srinivasarao P <spathi@codeaurora.org>