netfilter: qtaguid: fix proc/.../stats uid filtered output

netfilter: qtaguid: fix proc/.../stats uid filtered output

"cat /proc/net/xt_qtaguid/stats"
for a non-priviledged UID would output multiple twice its own stats.
The fix tweaks the way lines are counted.

Non-root:
  idx iface acct_tag_hex uid_tag_int cnt_set ...
  2 wlan0 0x0 10022 0 ...
  3 wlan0 0x0 10022 1 ...
  4 wlan0 0x3010000000000000 10022 0 ...
  5 wlan0 0x3010000000000000 10022 1 ...

Root:
  idx iface acct_tag_hex uid_tag_int cnt_set
  2 wlan0 0x0 0 0 ...
  3 wlan0 0x0 0 1 ...
  4 wlan0 0x0 1000 0 ...
  ...
  12 wlan0 0x0 10022 0 ...
  13 wlan0 0x0 10022 1 ...
  ...
  18 wlan0 0x3010000000000000 10022 0 ...
  19 wlan0 0x3010000000000000 10022 1 ...

Change-Id: I3cae1f4fee616bc897831350374656b0c718c45b
Signed-off-by: JP Abgrall <jpa@google.com>