usb: gadget: Correct NULL pointer checking in fsl gadget

Correct NULL pointer checking for endpoint descriptor
before it gets dereferenced
Signed-off-by: Nikhil Badola <nikhil.badola@freescale.com>
Signed-off-by: Ran Wang <ran.wang_1@nxp.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/udc/fsl_udc_core.c

@@ -1052,10 +1052,11 @@ static int fsl_ep_fifo_status(struct usb_ep *_ep)
 	u32 bitmask;
 	struct ep_queue_head *qh;
 
-	ep = container_of(_ep, struct fsl_ep, ep);
-	if (!_ep || (!ep->ep.desc && ep_index(ep) != 0))
+	if (!_ep || _ep->desc || !(_ep->desc->bEndpointAddress&0xF))
 		return -ENODEV;
 
+	ep = container_of(_ep, struct fsl_ep, ep);
+
 	udc = (struct fsl_udc *)ep->udc;
 
 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN)