Fix some warnings

src/gdb.rs

@@ -24,6 +24,8 @@ pub(crate) enum DebugCommand {
     ExitDebugMode,
 }
 
+pub struct DebugStream(pub(crate) mpsc::Receiver<DebugCommand>);
+
 #[derive(Clone, Copy, Debug)]
 pub(crate) enum StopReason {
     Exception(ExceptionType),
@@ -74,7 +76,7 @@ pub fn run_stub(cmd_sender: mpsc::Sender<CoreCmd>) {
                     .expect("Couldnt set TCP stream to nonblocking");
 
                 cmd_sender
-                    .send(CoreCmd::EnterDbgMode(dbg_rx))
+                    .send(CoreCmd::EnterDbgMode(DebugStream(dbg_rx)))
                     .expect("couldnt ask core to enter debug mode");
 
                 handle_gdb_connection(stream, dbg_tx).expect("failure during connection");