[PATCH] serial: Fix using plain integer instead of Null pointer

[Sugaya Taichi <sugaya.taichi@xxxxxxxxxxxxx>]

Fix build warning that using plain integer as Null pointer.
This is reported by kbuild test robot.

Fixes: ba44dc043004 ("serial: Add Milbeaut serial control")
Signed-off-by: Sugaya Taichi <sugaya.taichi@xxxxxxxxxxxxx>
---
 drivers/tty/serial/milbeaut_usio.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/serial/milbeaut_usio.c b/drivers/tty/serial/milbeaut_usio.c
index d303b7d..4a10604 100644
--- a/drivers/tty/serial/milbeaut_usio.c
+++ b/drivers/tty/serial/milbeaut_usio.c
@@ -500,7 +500,7 @@ static int __init mlb_usio_early_console_setup(struct earlycon_device *device,
 
 static int mlb_usio_probe(struct platform_device *pdev)
 {
-	struct clk *clk = devm_clk_get(&pdev->dev, 0);
+	struct clk *clk = devm_clk_get(&pdev->dev, NULL);
 	struct uart_port *port;
 	struct resource *res;
 	int index = 0;
-- 
1.9.1