[PATCH v3] thermal/drivers/rcar: fix error checking in probe()

[Dan Carpenter <error27@gmail.com>]

This code accidentally calls thermal_zone_device_enable() before checking
whether thermal_zone_device_register_with_trips() failed.  Move the call
until later to avoid an error pointer dereference of "priv->zone".

The driver works differently depending on if we are using OF thermal or
not.  We use thermal_add_hwmon_sysfs() if we are using OF thermal and
call thermal_zone_device_enable() if not.  We can share same error check
for if either of these fail.

Moving the thermal_zone_device_enable() call is a bit cleaner as well.
The original code used a three step process to cleanup:
1. Call thermal_zone_device_unregister() to cleanup.
2. Set priv->zone to an error pointer to preserve the error code.
3. Set priv->zone to NULL to avoid a second call to
   thermal_zone_device_unregister() in the rcar_thermal_remove()
   function.

Now we can just do a direct goto error_unregister and rcar_thermal_remove()
handles the cleanup properly.

Fixes: bbcf90c0646a ("thermal: Explicitly enable non-changing thermal zone devices")
Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2: Use the correct fixes tag and re-write the check in a cleaner way.
v3: Share the same error checking as a further cleanup.  The
    thermal_add_hwmon_sysfs() and thermal_zone_device_enable() functions
    really do serve the same purpose even though their names are
    different.

 drivers/thermal/renesas/rcar_thermal.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/thermal/renesas/rcar_thermal.c b/drivers/thermal/renesas/rcar_thermal.c
index 6e5dcac5d47a..fd686da9252e 100644
--- a/drivers/thermal/renesas/rcar_thermal.c
+++ b/drivers/thermal/renesas/rcar_thermal.c
@@ -492,12 +492,6 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 				"rcar_thermal", trips, ARRAY_SIZE(trips), priv,
 						&rcar_thermal_zone_ops, NULL, 0,
 						idle);
-
-			ret = thermal_zone_device_enable(priv->zone);
-			if (ret) {
-				thermal_zone_device_unregister(priv->zone);
-				priv->zone = ERR_PTR(ret);
-			}
 		}
 		if (IS_ERR(priv->zone)) {
 			dev_err(dev, "can't register thermal zone\n");
@@ -506,11 +500,12 @@ static int rcar_thermal_probe(struct platform_device *pdev)
 			goto error_unregister;
 		}
 
-		if (chip->use_of_thermal) {
+		if (chip->use_of_thermal)
 			ret = thermal_add_hwmon_sysfs(priv->zone);
-			if (ret)
-				goto error_unregister;
-		}
+		else
+			ret = thermal_zone_device_enable(priv->zone);
+		if (ret)
+			goto error_unregister;
 
 		rcar_thermal_irq_enable(priv);
 
-- 
2.53.0