isdn: hisax: add missing usb_free_urb

Add missing usb_free_urb() on failure path in st5481_setup_usb().

Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: NMarina Makienko <makienko@ispras.ru>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/isdn/hisax/st5481_usb.c

@@ -294,13 +294,13 @@ int st5481_setup_usb(struct st5481_adapter *adapter)
 	// Allocate URBs and buffers for interrupt endpoint
 	urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!urb) {
-		return -ENOMEM;
+		goto err1;
 	}
 	intr->urb = urb;
 
 	buf = kmalloc(INT_PKT_SIZE, GFP_KERNEL);
 	if (!buf) {
-		return -ENOMEM;
+		goto err2;
 	}
 
 	endpoint = &altsetting->endpoint[EP_INT-1];
@@ -313,6 +313,14 @@ int st5481_setup_usb(struct st5481_adapter *adapter)
 			 endpoint->desc.bInterval);
 
 	return 0;
+err2:
+	usb_free_urb(intr->urb);
+	intr->urb = NULL;
+err1:
+	usb_free_urb(ctrl->urb);
+	ctrl->urb = NULL;
+
+	return -ENOMEM;
 }
 
 /*