mpls: Better error code for unsupported option.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 0f2833e..5c99e3f 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -348,7 +348,7 @@
 		goto errout;
 
 	/* Append makes no sense with mpls */
-	err = -EINVAL;
+	err = -EOPNOTSUPP;
 	if (cfg->rc_nlflags & NLM_F_APPEND)
 		goto errout;