hwrng: omap - Only fail if pm_runtime_get_sync returns < 0

BugLink: http://bugs.launchpad.net/bugs/1638267

commit ad8529fd upstream.

Currently omap-rng checks the return value of pm_runtime_get_sync and
reports failure if anything is returned, however it should be checking
if ret < 0 as pm_runtime_get_sync return 0 on success but also can return
1 if the device was already active which is not a failure case. Only
values < 0 are actual failures.

Fixes: 61dc0a44 ("hwrng: omap - Fix assumption that runtime_get_sync will always succeed")
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

drivers/char/hw_random/omap-rng.c

@@ -385,7 +385,7 @@ static int omap_rng_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(&pdev->dev);
 	ret = pm_runtime_get_sync(&pdev->dev);
-	if (ret) {
+	if (ret < 0) {
 		dev_err(&pdev->dev, "Failed to runtime_get device: %d\n", ret);
 		pm_runtime_put_noidle(&pdev->dev);
 		goto err_ioremap;
@@ -443,7 +443,7 @@ static int __maybe_unused omap_rng_resume(struct device *dev)
 	int ret;
 
 	ret = pm_runtime_get_sync(dev);
-	if (ret) {
+	if (ret < 0) {
 		dev_err(dev, "Failed to runtime_get device: %d\n", ret);
 		pm_runtime_put_noidle(dev);
 		return ret;