cdx: Unlock on error path in rescan_store()

We added locking to this function but these two error paths were
accidentally overlooked.

Fixes: f0af816 ("cdx: Introduce lock to protect controller ops")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://lore.kernel.org/r/a7994b47-6f78-4e2c-a30a-ee5995d428ec@moroto.mountain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Dan Carpenter

drivers/cdx/cdx.c

@@ -607,7 +607,8 @@ static ssize_t rescan_store(const struct bus_type *bus,
 		pd = of_find_device_by_node(np);
 		if (!pd) {
 			of_node_put(np);
-			return -EINVAL;
+			count = -EINVAL;
+			goto unlock;
 		}
 
 		cdx = platform_get_drvdata(pd);
@@ -617,6 +618,7 @@ static ssize_t rescan_store(const struct bus_type *bus,
 		put_device(&pd->dev);
 	}
 
+unlock:
 	mutex_unlock(&cdx_controller_lock);
 
 	return count;