net/local: remove duplicate assert condition

Signed-off-by: chao.an <anchao@xiaomi.com>

net/local/local_listen.c

@@ -107,8 +107,7 @@ int local_listen(FAR struct socket *psock, int backlog)
     {
       /* The connection should not reside in any other list */
 
-      DEBUGASSERT(server->lc_node.flink == NULL &&
-                  server->lc_node.flink == NULL);
+      DEBUGASSERT(server->lc_node.flink == NULL);
 
       /* And change the server state to listing */