[NET_SCHED]: Propagate nla_parse return value

nla_parse() returns more detailed errno codes, propagate them back on
error.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/act_police.c b/net/sched/act_police.c
index 3af5759..c0fce9b 100644
--- a/net/sched/act_police.c
+++ b/net/sched/act_police.c
@@ -129,9 +129,13 @@
 	struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
 	int size;
 
-	if (nla == NULL || nla_parse_nested(tb, TCA_POLICE_MAX, nla, NULL) < 0)
+	if (nla == NULL)
 		return -EINVAL;
 
+	err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, NULL);
+	if (err < 0)
+		return err;
+
 	if (tb[TCA_POLICE_TBF] == NULL)
 		return -EINVAL;
 	size = nla_len(tb[TCA_POLICE_TBF]);