usb: gadget: udc: avoid dereference before NULL check in ep_queue

Coverity: CID 1260069
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/gadget/udc/bdc/bdc_ep.c

@@ -718,10 +718,11 @@ static int ep_queue(struct bdc_ep *ep, struct bdc_req *req)
 	struct bdc *bdc;
 	int ret = 0;
 
-	bdc = ep->bdc;
 	if (!req || !ep || !ep->usb_ep.desc)
 		return -EINVAL;
 
+	bdc = ep->bdc;
+
 	req->usb_req.actual = 0;
 	req->usb_req.status = -EINPROGRESS;
 	req->epnum = ep->ep_num;