drivers/usb/gadget/core.c: Fix GCC 4.6 warning

Fix:
core.c: In function 'usbd_device_event_irq':
core.c:596:21: warning: variable 'state' set but not used
[-Wunused-but-set-variable]

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Remy Bohmer <linux@bohmer.net>
Acked-by: Remy Bohmer <linux@bohmer.net>
Acked-by: Marek Vasut <marek.vasut@gmail.com>

drivers/usb/gadget/core.c

@@ -671,9 +671,9 @@ void usbd_device_event_irq (struct usb_device_instance *device, usb_device_event
 		usbdbg("event %d - not handled",event);
 		break;
 	}
-	/*usbdbg("%s event: %d oldstate: %d newstate: %d status: %d address: %d",
+	debug("%s event: %d oldstate: %d newstate: %d status: %d address: %d",
 		device->name, event, state,
-		device->device_state, device->status, device->address); */
+		device->device_state, device->status, device->address);
 
 	/* tell the bus interface driver */
 	if( device->event ) {