warning_fix: fix warnings when build with cargo-1.68.0

Fixes: #6593

Signed-off-by: alex.lyn <alex.lyn@antgroup.com>

src/tools/agent-ctl/src/main.rs

@@ -314,7 +314,7 @@ fn real_main() -> Result<()> {
             Ok(())
         }
         "connect" => connect(name, args),
-        _ => return Err(anyhow!(format!("invalid sub-command: {:?}", subcmd))),
+        _ => Err(anyhow!(format!("invalid sub-command: {:?}", subcmd))),
     }
 }