sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()

BugLink: https://bugs.launchpad.net/bugs/1830176

[ Upstream commit ac0cdb3d ]

Add the missing uart_unregister_driver() and i2c_del_driver() before return
from sc16is7xx_init() in the error handling case.
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/tty/serial/sc16is7xx.c

@@ -1448,7 +1448,7 @@ static int __init sc16is7xx_init(void)
 	ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
 	if (ret < 0) {
 		pr_err("failed to init sc16is7xx i2c --> %d\n", ret);
-		return ret;
+		goto err_i2c;
 	}
 #endif
 
@@ -1456,10 +1456,18 @@ static int __init sc16is7xx_init(void)
 	ret = spi_register_driver(&sc16is7xx_spi_uart_driver);
 	if (ret < 0) {
 		pr_err("failed to init sc16is7xx spi --> %d\n", ret);
-		return ret;
+		goto err_spi;
 	}
 #endif
 	return ret;
+
+err_spi:
+#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
+	i2c_del_driver(&sc16is7xx_i2c_uart_driver);
+#endif
+err_i2c:
+	uart_unregister_driver(&sc16is7xx_uart);
+	return ret;
 }
 module_init(sc16is7xx_init);