USB: make usb_mark_last_busy use pm_runtime_mark_last_busy

Since the runtime-PM core already defines a .last_busy field in
device.power, this patch uses it to replace the .last_busy field
defined in usb_device and uses pm_runtime_mark_last_busy to implement
usb_mark_last_busy.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 35fe6ab..7d22b33 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -20,6 +20,7 @@
 #include <linux/completion.h>	/* for struct completion */
 #include <linux/sched.h>	/* for current && schedule_timeout */
 #include <linux/mutex.h>	/* for struct mutex */
+#include <linux/pm_runtime.h>	/* for runtime PM */
 
 struct usb_device;
 struct usb_driver;
@@ -407,7 +408,6 @@
  * @quirks: quirks of the whole device
  * @urbnum: number of URBs submitted for the whole device
  * @active_duration: total time device is not suspended
- * @last_busy: time of last use
  * @autosuspend_delay: in jiffies
  * @connect_time: time device was first connected
  * @do_remote_wakeup:  remote wakeup should be enabled
@@ -481,7 +481,6 @@
 	unsigned long active_duration;
 
 #ifdef CONFIG_PM
-	unsigned long last_busy;
 	int autosuspend_delay;
 	unsigned long connect_time;
 
@@ -527,7 +526,7 @@
 
 static inline void usb_mark_last_busy(struct usb_device *udev)
 {
-	udev->last_busy = jiffies;
+	pm_runtime_mark_last_busy(&udev->dev);
 }
 
 #else