USB: use bus_to_hdc instead of container_of

We defined bus_to_hdc for that, use it.
Signed-off-by: Yuanhan Liu <yliu.null@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/usb.c

@@ -370,14 +370,14 @@ struct usb_device *usb_alloc_dev(struct usb_device *parent,
 				 struct usb_bus *bus, unsigned port1)
 {
 	struct usb_device *dev;
-	struct usb_hcd *usb_hcd = container_of(bus, struct usb_hcd, self);
+	struct usb_hcd *usb_hcd = bus_to_hcd(bus);
 	unsigned root_hub = 0;
 
 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (!dev)
 		return NULL;
 
-	if (!usb_get_hcd(bus_to_hcd(bus))) {
+	if (!usb_get_hcd(usb_hcd)) {
 		kfree(dev);
 		return NULL;
 	}