Use snake-case for cmd_id.

src/handlers.rs

@@ -103,7 +103,7 @@ fn reply_error(d: *const DenoC, cmd_id: u32, msg: &String) {
   let mut builder = flatbuffers::FlatBufferBuilder::new();
   // println!("reply_error{}", msg);
   let args = msg::BaseArgs {
-    cmdId: cmd_id,
+    cmd_id: cmd_id,
     error: Some(builder.create_string(msg)),
     ..Default::default()
   };

src/msg.fbs

@@ -18,7 +18,7 @@ union Any {
 }
 
 table Base {
-  cmdId: uint32;
+  cmd_id: uint32;
   error: string;
   msg: Any;
 }