net/sched: act_pedit: fix memory leak when IDR allocation fails

tcf_idr_check_alloc() can return a negative value, on allocation failures
(-ENOMEM) or IDR exhaustion (-ENOSPC): don't leak keys_ex in these cases.

Fixes: 0190c1d4 ("net: sched: atomically check-allocate action")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/act_pedit.c

@@ -201,7 +201,8 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 			goto out_release;
 		}
 	} else {
-		return err;
+		ret = err;
+		goto out_free;
 	}
 
 	p = to_pedit(*a);