net_sched: cls_api: fix return value for non-existant classifiers

cls_api should return ENOENT when the requested classifier doesn't
exist.

Signed-off-by: Patrick McHardy <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/sched/cls_api.c

···
 		tp = kzalloc(sizeof(*tp), GFP_KERNEL);
 		if (tp == NULL)
 			goto errout;
-		err = -EINVAL;
+		err = -ENOENT;
 		tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
 		if (tp_ops == NULL) {
 #ifdef CONFIG_KMOD