usb: gadget: composite: dequeue cdev->req before free it in composite_dev_cleanup

This patch try to dequeue the cdev->req to guarantee the request is not queued
before free it.

Signed-off-by: Li Jun <b47624@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index f801519..6935a82 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -1956,6 +1956,7 @@
 	}
 	if (cdev->req) {
 		kfree(cdev->req->buf);
+		usb_ep_dequeue(cdev->gadget->ep0, cdev->req);
 		usb_ep_free_request(cdev->gadget->ep0, cdev->req);
 	}
 	cdev->next_string_id = 0;