[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_gact.c b/net/sched/act_gact.c
index 5402cf8..df214d4 100644
--- a/net/sched/act_gact.c
+++ b/net/sched/act_gact.c
@@ -61,10 +61,15 @@
 	struct tcf_gact *gact;
 	struct tcf_common *pc;
 	int ret = 0;
+	int err;
 
-	if (nla == NULL || nla_parse_nested(tb, TCA_GACT_MAX, nla, NULL) < 0)
+	if (nla == NULL)
 		return -EINVAL;
 
+	err = nla_parse_nested(tb, TCA_GACT_MAX, nla, NULL);
+	if (err < 0)
+		return err;
+
 	if (tb[TCA_GACT_PARMS] == NULL ||
 	    nla_len(tb[TCA_GACT_PARMS]) < sizeof(*parm))
 		return -EINVAL;