PM: Add parent information to timing messages

Add parent information to the messages printed by the suspend/resume
core when initcall_debug is set.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index a5142bd..6ca5cdf 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -271,8 +271,9 @@
 	ktime_t calltime, delta, rettime;
 
 	if (initcall_debug) {
-		pr_info("calling  %s_i+ @ %i\n",
-				dev_name(dev), task_pid_nr(current));
+		pr_info("calling  %s+ @ %i, parent: %s\n",
+				dev_name(dev), task_pid_nr(current),
+				dev->parent ? dev_name(dev->parent) : "none");
 		calltime = ktime_get();
 	}