net_sched: fix two more memory leaks in cls_tcindex

net_sched: fix two more memory leaks in cls_tcindex

BugLink: https://bugs.launchpad.net/bugs/1825942
struct tcindex_filter_result contains two parts:
struct tcf_exts and struct tcf_result.

For the local variable 'cr', its exts part is never used but
initialized without being released properly on success path. So
just completely remove the exts part to fix this leak.

For the local variable 'new_filter_result', it is never properly
released if not used by 'r' on success path.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 1db817e75f5b9387b8db11e37d5f0624eb9223e0)
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Acked-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>