usb: gadget: net2280: use generic map/unmap routines

those routines have everything we need to map/unmap
USB requests and it's better to use them.
Signed-off-by: NFelipe Balbi <balbi@ti.com>

drivers/usb/gadget/net2280.c

@@ -806,12 +806,8 @@ done (struct net2280_ep *ep, struct net2280_request *req, int status)
 		status = req->req.status;
 
 	dev = ep->dev;
-	if (req->mapped) {
-		pci_unmap_single (dev->pdev, req->req.dma, req->req.length,
-			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
-		req->req.dma = DMA_ADDR_INVALID;
-		req->mapped = 0;
-	}
+	if (ep->dma)
+		usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);
 
 	if (status && status != -ESHUTDOWN)
 		VDEBUG (dev, "complete %s req %p stat %d len %u/%u\n",
@@ -857,10 +853,13 @@ net2280_queue (struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
 		return -EOPNOTSUPP;
 
 	/* set up dma mapping in case the caller didn't */
-	if (ep->dma && _req->dma == DMA_ADDR_INVALID) {
-		_req->dma = pci_map_single (dev->pdev, _req->buf, _req->length,
-			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
-		req->mapped = 1;
+	if (ep->dma) {
+		int ret;
+
+		ret = usb_gadget_map_request(&dev->gadget, _req,
+				ep->is_in);
+		if (ret)
+			return ret;
 	}
 
 #if 0