PM / QoS: Rename local variable in dev_pm_qos_add_ancestor_request()

Local variable 'error' in dev_pm_qos_add_ancestor_request() need
not contain error codes only, so rename it to 'ret'.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/power/qos.c b/drivers/base/power/qos.c
index ff46387..d213495 100644
--- a/drivers/base/power/qos.c
+++ b/drivers/base/power/qos.c
@@ -542,19 +542,19 @@
 				    struct dev_pm_qos_request *req, s32 value)
 {
 	struct device *ancestor = dev->parent;
-	int error = -ENODEV;
+	int ret = -ENODEV;
 
 	while (ancestor && !ancestor->power.ignore_children)
 		ancestor = ancestor->parent;
 
 	if (ancestor)
-		error = dev_pm_qos_add_request(ancestor, req,
-					       DEV_PM_QOS_LATENCY, value);
+		ret = dev_pm_qos_add_request(ancestor, req,
+					     DEV_PM_QOS_LATENCY, value);
 
-	if (error < 0)
+	if (ret < 0)
 		req->dev = NULL;
 
-	return error;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_qos_add_ancestor_request);