net_sched: fix a resource leak in tcindex_set_parms()

Jakub noticed there is a potential resource leak in
tcindex_set_parms(): when tcindex_filter_result_init() fails
and it jumps to 'errout1' which doesn't release the memory
and resources allocated by tcindex_alloc_perfect_hash().

We should just jump to 'errout_alloc' which calls
tcindex_free_perfect_hash().

Fixes: b9a24bb7 ("net_sched: properly handle failure case of tcf_exts_init()")
Reported-by: Jakub Kicinski <kuba@kernel.org>
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>