Remove the redundant bound_socket() from ListenStream

There is no need to get the bound socket by cloning the first element
from `self.backlog_sockets`. If we want a bound socket, we can always
use `self.bound_socket` directly.

services/libs/jinux-std/src/net/socket/ip/stream/listen.rs

@@ -105,7 +105,7 @@ impl ListenStream {
     }
 
     pub fn local_endpoint(&self) -> Result<IpEndpoint> {
-        self.bound_socket()
+        self.bound_socket
             .local_endpoint()
             .ok_or_else(|| Error::with_message(Errno::EINVAL, "does not has remote endpoint"))
     }
@@ -114,10 +114,6 @@ impl ListenStream {
         self.pollee.poll(mask, poller)
     }
 
-    fn bound_socket(&self) -> Arc<AnyBoundSocket> {
-        self.backlog_sockets.read()[0].bound_socket.clone()
-    }
-
     fn update_io_events(&self) {
         // The lock should be held to avoid data races
         let backlog_sockets = self.backlog_sockets.read();