dccp: return -EINVAL on invalid feature length

dccp_feat_change() validates length and on error is returning 1.
This happens to work since call chain is checking for 0 == success,
but this is returned to userspace, so make it a real error value.
Signed-off-by: NChris Wright <chrisw@sous-sol.org>
Acked-by: NArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/dccp/feat.c

@@ -32,7 +32,7 @@ int dccp_feat_change(struct dccp_minisock *dmsk, u8 type, u8 feature,
 
 	if (len > 3) {
 		DCCP_WARN("invalid length %d\n", len);
-		return 1;
+		return -EINVAL;
 	}
 	/* XXX add further sanity checks */