serial: stm32: Ignore return value of uart_remove_one_port() in .remove()

[ Upstream commit 6bd6cd2 ]

Returning early from stm32_usart_serial_remove() results in a resource
leak as several cleanup functions are not called. The driver core ignores
the return value and there is no possibility to clean up later.

uart_remove_one_port() only returns non-zero if there is some
inconsistency (i.e. stm32_usart_driver.state[port->line].uart_port == NULL).
This should never happen, and even if it does it's a bad idea to exit
early in the remove callback without cleaning up.

This prepares changing the prototype of struct platform_driver::remove to
return void. See commit 5c5a768 ("platform: Provide a remove callback
that returns no value") for further details about this quest.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230512173810.131447-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Change-Id: I5f9e87e6ffacfe32332497f034191bed7eacaa7e
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/linux-stm32/+/320775
ACI: CIBUILD <MDG-smet-aci-builds@list.st.com>
Reviewed-by: Amelie DELAUNAY <amelie.delaunay@foss.st.com>
ACI: CITOOLS <MDG-smet-aci-reviews@list.st.com>
Domain-Review: Amelie DELAUNAY <amelie.delaunay@foss.st.com>

Author: Uwe Kleine-König

drivers/tty/serial/stm32-usart.c

@@ -2044,13 +2044,10 @@ static int stm32_usart_serial_remove(struct platform_device *pdev)
 	struct uart_port *port = platform_get_drvdata(pdev);
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-	int err;
 	u32 cr3;
 
 	pm_runtime_get_sync(&pdev->dev);
-	err = uart_remove_one_port(&stm32_usart_driver, port);
-	if (err)
-		return(err);
+	uart_remove_one_port(&stm32_usart_driver, port);
 
 	pm_runtime_disable(&pdev->dev);
 	pm_runtime_set_suspended(&pdev->dev);