net_sched: act_bpf: remove unnecessary copy

Fix harmless typo and avoid unnecessary copy of empty 'prog' into
unused 'strcut tcf_bpf_cfg old'.

Fixes: f4eaed28c7 ("act_bpf: fix memory leaks when replacing bpf programs")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/act_bpf.c

@@ -327,7 +327,7 @@ static int tcf_bpf_init(struct net *net, struct nlattr *nla,
 	prog = to_bpf(act);
 	spin_lock_bh(&prog->tcf_lock);
 
-	if (ret != ACT_P_CREATED)
+	if (res != ACT_P_CREATED)
 		tcf_bpf_prog_fill_cfg(prog, &old);
 
 	prog->bpf_ops = cfg.bpf_ops;