XML: Do not add empty Value node for nodes with child nodes in TNDS

This fixes some validation issues against DM_ddf DTD that were caused by
the conversion from the internal tree structure to TNDS. Only the leaf
nodes are supposed to have the Value node.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

src/utils/xml-utils.c

@@ -246,7 +246,9 @@ static void node_to_tnds(struct xml_node_ctx *ctx, xml_node_t *out,
 			xml_node_create_text(ctx, tnds, NULL, "Path", uri);
 
 		val = get_val(ctx, node);
-		xml_node_create_text(ctx, tnds, NULL, "Value", val ? val : "");
+		if (val || !xml_node_first_child(ctx, node))
+			xml_node_create_text(ctx, tnds, NULL, "Value",
+					     val ? val : "");
 		xml_node_get_text_free(ctx, val);
 
 		new_uri = add_path(uri, name);