[Bluetooth] Initialize interval of ISOC URB's

The urb->interval value must be set when submitting an ISOC URB. If this
is not done, the usb_submit_urb() call fails.

Patch from Andreas Kemnade <akemnade@informatik.uni-bremen.de>

drivers/bluetooth/hci_usb.c

@@ -264,6 +264,8 @@ static int hci_usb_isoc_rx_submit(struct hci_usb *husb)
 	urb->pipe     = usb_rcvisocpipe(husb->udev, husb->isoc_in_ep->desc.bEndpointAddress);
 	urb->complete = hci_usb_rx_complete;
 
+	urb->interval = husb->isoc_in_ep->desc.bInterval;
+
 	urb->transfer_buffer_length = size;
 	urb->transfer_buffer = buf;
 	urb->transfer_flags  = URB_ISO_ASAP;
@@ -492,6 +494,8 @@ static inline int hci_usb_send_isoc(struct hci_usb *husb, struct sk_buff *skb)
 	urb->complete = hci_usb_tx_complete;
 	urb->transfer_flags = URB_ISO_ASAP;
 
+	urb->interval = husb->isoc_out_ep->desc.bInterval;
+
 	urb->transfer_buffer = skb->data;
 	urb->transfer_buffer_length = skb->len;