Refactor logging messages in operators and subgraph nodes

PiperOrigin-RevId: 314654928
diff --git a/src/xnnpack/operator.h b/src/xnnpack/operator.h
index 1cfc3b1..cd39d62 100644
--- a/src/xnnpack/operator.h
+++ b/src/xnnpack/operator.h
@@ -45,7 +45,7 @@
 };
 
 enum xnn_operator_type {
-  xnn_operator_type_none = 0,
+  xnn_operator_type_invalid = 0,
   xnn_operator_type_add_nc_f32,
   xnn_operator_type_add_nd_f32,
   xnn_operator_type_add_nc_q8,