examples: use select! instead of join! in connect_(tcp|udp) examples (#7842)

examples/connect-tcp.rs

@@ -64,8 +64,10 @@ pub async fn connect(
         })
         .map(Ok);
 
-    match future::join(sink.send_all(&mut stdin), stdout.send_all(&mut stream)).await {
-        (Err(e), _) | (_, Err(e)) => Err(e.into()),
-        _ => Ok(()),
+    tokio::select! {
+        r = sink.send_all(&mut stdin) => r?,
+        r = stdout.send_all(&mut stream) => r?,
     }
+
+    Ok(())
 }

examples/connect-udp.rs

@@ -59,7 +59,10 @@ pub async fn connect(
     let socket = UdpSocket::bind(&bind_addr).await?;
     socket.connect(addr).await?;
 
-    tokio::try_join!(send(stdin, &socket), recv(stdout, &socket))?;
+    tokio::select! {
+        r = send(stdin, &socket) => r?,
+        r = recv(stdout, &socket) => r?,
+    }
 
     Ok(())
 }