hwrng: exynos - Disable runtime PM on probe failure

Add proper error path (for disabling runtime PM) when registering of
hwrng fails.

Fixes: b329669ea0b5 ("hwrng: exynos - Add support for Exynos random number generator")
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/char/hw_random/exynos-rng.c

@@ -119,6 +119,7 @@ static int exynos_rng_probe(struct platform_device *pdev)
 {
 	struct exynos_rng *exynos_rng;
 	struct resource *res;
+	int ret;
 
 	exynos_rng = devm_kzalloc(&pdev->dev, sizeof(struct exynos_rng),
 					GFP_KERNEL);
@@ -146,7 +147,13 @@ static int exynos_rng_probe(struct platform_device *pdev)
 	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
-	return devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
+	ret = devm_hwrng_register(&pdev->dev, &exynos_rng->rng);
+	if (ret) {
+		pm_runtime_dont_use_autosuspend(&pdev->dev);
+		pm_runtime_disable(&pdev->dev);
+	}
+
+	return ret;
 }
 
 static int __maybe_unused exynos_rng_runtime_suspend(struct device *dev)