TcUtils: allow ignoring netlink error code ENOENT

Ignore this error code during DEL operations.

It is returned when the specific thing to be deleted
is not found and is therefore a valid response.

Gets rid of 30+ logs worth of:
  E TcUtils : NLMSG_ERROR message return error: -2
during netd startup (cleanup phase).

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: Ie542f8ff418dbed604eea5b31b87f9b974ccdbcb
1 file changed