[PATCH v3] serial: txx9: add missing platform_driver_unregister() on error in serial_txx9_init

[Qinglang Miao]

Add the missing platform_driver_unregister() before return
from serial_txx9_init in the error handling case when failed
to register serial_txx9_pci_driver with macro ENABLE_SERIAL_TXX9_PCI
defined.

Fixes: ab4382d27412 ("tty: move drivers/serial/ to drivers/tty/serial/")
Signed-off-by: Qinglang Miao <miaoqingl...@huawei.com>
---
 v2: v1 introduced a label named unreg_platform_drv which was unused
     when ENABLE_SERIAL_TXX9_PCI not defined. It's not resonable enough,
     so remove it and do simply check in <#ifdef ... #endif>.
 v3: add version update message.

 drivers/tty/serial/serial_txx9.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/serial/serial_txx9.c b/drivers/tty/serial/serial_txx9.c
index b4d89e317..7a07e7272 100644
--- a/drivers/tty/serial/serial_txx9.c
+++ b/drivers/tty/serial/serial_txx9.c
@@ -1280,6 +1280,9 @@ static int __init serial_txx9_init(void)
 
 #ifdef ENABLE_SERIAL_TXX9_PCI
        ret = pci_register_driver(&serial_txx9_pci_driver);
+       if (ret) {
+               platform_driver_unregister(&serial_txx9_plat_driver);
+       }
 #endif
        if (ret == 0)
                goto out;
-- 
2.23.0