usbip: tools: Fix detach_port() invalid port error path

The detach_port() doesn't return error
when detach is attempted on an invalid port.

Fixes: 40ecdeb ("usbip: usbip_detach: fix to check for invalid ports")
Cc: stable@vger.kernel.org
Reviewed-by: Hongren Zheng <i@zenithal.me>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Zongmin Zhou <zhouzongmin@kylinos.cn>
Link: https://lore.kernel.org/r/20241024022700.1236660-1-min_halo@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Zongmin Zhou

tools/usb/usbip/src/usbip_detach.c

@@ -68,6 +68,7 @@ static int detach_port(char *port)
 	}
 
 	if (!found) {
+		ret = -1;
 		err("Invalid port %s > maxports %d",
 			port, vhci_driver->nports);
 		goto call_driver_close;