watchdog: starfive: Check pm_runtime_enabled() before decrementing usage counter

In the probe function, pm_runtime_put_sync() will fail on platform with
runtime PM disabled.
Check if runtime PM is enabled before calling pm_runtime_put_sync() to
fix it.

Fixes: db728ea9 ("drivers: watchdog: Add StarFive Watchdog driver")
Signed-off-by: Xingyu Wu <xingyu.wu@starfivetech.com>
Signed-off-by: Ley Foon Tan <leyfoon.tan@starfivetech.com>
Signed-off-by: Ji Sheng Teoh <jisheng.teoh@starfivetech.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20240119082722.1133024-1-jisheng.teoh@starfivetech.comSigned-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

drivers/watchdog/starfive-wdt.c

@@ -494,8 +494,13 @@ static int starfive_wdt_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_exit;
 
-	if (!early_enable)
-		pm_runtime_put_sync(&pdev->dev);
+	if (!early_enable) {
+		if (pm_runtime_enabled(&pdev->dev)) {
+			ret = pm_runtime_put_sync(&pdev->dev);
+			if (ret)
+				goto err_exit;
+		}
+	}
 
 	return 0;