Bluetooth: Return ENODATA in hci_req_run

In case the HCI request queue is empty, hci_req_run should return
ENODATA instead of EINVAL. This way, hci_req_run returns a more
meaningful error value.
Signed-off-by: NAndre Guedes <andre.guedes@openbossa.org>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>

net/bluetooth/hci_core.c

@@ -2452,7 +2452,7 @@ int hci_req_run(struct hci_request *req, hci_req_complete_t complete)
 
 	/* Do not allow empty requests */
 	if (skb_queue_empty(&req->cmd_q))
-		return -EINVAL;
+		return -ENODATA;
 
 	skb = skb_peek_tail(&req->cmd_q);
 	bt_cb(skb)->req.complete = complete;