[Bluetooth] Remove unused functions and cleanup symbol exports

This patch removes the unused bt_dump() function and it also removes
its BT_DMP macro. It also unexports the hci_dev_get(), hci_send_cmd()
and hci_si_event() functions.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

net/bluetooth/hci_event.c

@@ -1040,4 +1040,3 @@ void hci_si_event(struct hci_dev *hdev, int type, int dlen, void *data)
 	hci_send_to_sock(hdev, skb);
 	kfree_skb(skb);
 }
-EXPORT_SYMBOL(hci_si_event);