Prefix _ to unused variables.

Signed-off-by: OGINO Masanori <[email protected]>

Author: omasanori

src/libstd/io/extensions.rs

@@ -366,7 +366,7 @@ mod test {
     fn push_bytes_fail_reset_len() {
         // push_bytes unsafely sets the vector length. This is testing that
         // upon failure the length is reset correctly.
-        let reader = ErroringLaterReader {
+        let _reader = ErroringLaterReader {
             count: 0,
         };
         // FIXME (#7049): Figure out some other way to do this.

src/libstd/io/net/tcp.rs

@@ -632,7 +632,7 @@ mod test {
 
         spawn(proc() {
             port.recv();
-            let stream = TcpStream::connect(addr);
+            let _stream = TcpStream::connect(addr);
             // Close
             port.recv();
         });
@@ -641,12 +641,12 @@ mod test {
             let mut acceptor = TcpListener::bind(addr).listen();
             chan.send(());
             {
-                let stream = acceptor.accept();
+                let _stream = acceptor.accept();
                 // Close client
                 chan.send(());
             }
             // Close listener
         }
-        let listener = TcpListener::bind(addr);
+        let _listener = TcpListener::bind(addr);
     })
 }