Locate port being listened to by counting-from-the-right (again)

In the process of cleaning up the magic numbers in a previous CL,
we opted to switch from -2 to 8 while moving the value into a
constant. This turned out to be unstable.

BUG=none
TEST=security_NetworkListeners will pass

Change-Id: Ie68521e4da6a22d58e1e58499fda99236fefe003
Reviewed-on: https://gerrit.chromium.org/gerrit/58702
Commit-Queue: Jim Hebert <jimhebert@chromium.org>
Tested-by: Jim Hebert <jimhebert@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
1 file changed