serial: samsung: missing uart_unregister_driver() on error in s3c24xx_serial_modinit()

Add the missing uart_unregister_driver() before return from
s3c24xx_serial_modinit() in the error handling case.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/samsung.c

@@ -1798,7 +1798,13 @@ static int __init s3c24xx_serial_modinit(void)
 		return ret;
 	}
 
-	return platform_driver_register(&samsung_serial_driver);
+	ret = platform_driver_register(&samsung_serial_driver);
+	if (ret < 0) {
+		pr_err("Failed to register platform driver\n");
+		uart_unregister_driver(&s3c24xx_uart_drv);
+	}
+
+	return ret;
 }
 
 static void __exit s3c24xx_serial_modexit(void)