Bluetooth: Fix potential memory leak

If command is added to req then it should be freed in case if
hdev is down or HCI_ADVERTISING flag is set.

This introduces a helper in hci_request to purge the cmd_q
to make cmd_q internal to hci_request which is used to fix
the leak.

This also replace accessing of cmd_q in hci_conn with the
new helper.

Signed-off-by: Jaganath Kanakkassery <jaganathx.kanakkassery@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
diff --git a/net/bluetooth/hci_request.c b/net/bluetooth/hci_request.c
index b73ac14..7f28d17 100644
--- a/net/bluetooth/hci_request.c
+++ b/net/bluetooth/hci_request.c
@@ -41,6 +41,11 @@ void hci_req_init(struct hci_request *req, struct hci_dev *hdev)
 	req->err = 0;
 }
 
+void hci_req_purge(struct hci_request *req)
+{
+	skb_queue_purge(&req->cmd_q);
+}
+
 static int req_run(struct hci_request *req, hci_req_complete_t complete,
 		   hci_req_complete_skb_t complete_skb)
 {