ANDROID: xt_quota2: remove trailing junk which might have a digit in it

ANDROID: xt_quota2: remove trailing junk which might have a digit in it

Make sure string only contains the characters specified by userspace.

Fix cherry-picked from xtables-extensions project

Signed-off-by: Sam Liddicott <sam@liddicott.com>
Mot-CRs-fixed: (CR)
CVE-Fixed: CVE-2021-0961

Bug: 196046570
Test: passed netd test suites
Fixes: 10cda83af99d ("ANDROID: netfilter: xt_quota2: adding the
original quota2 from xtables-addons")
Signed-off-by: Todd Kjos <tkjos@google.com>
(cherry picked from https://git.code.sf.net/p/xtables-addons/xtables-addons
bc2bcc383c70b293bd816c29523a952ca8736fb5)
Change-Id: I965448564906e5fbf0fe6d6414f44d9e257ea195
Signed-off-by: Gajjala Chakradhar <gajjalac@motorola.com>
Reviewed-on: https://gerrit.mot.com/2123622
SLTApproved: Slta Waiver
SME-Granted: SME Approvals Granted
Tested-by: Jira Key
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key
(cherry picked from commit 625eb505d4c123adcc699c2a73aeec1390adf03c)