Bluetooth: remove lock from struct conn_hash

It isn't used anywhere.
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>

include/net/bluetooth/hci_core.h

@@ -61,7 +61,6 @@ struct inquiry_cache {
 
 struct hci_conn_hash {
 	struct list_head list;
-	spinlock_t       lock;
 	unsigned int     acl_num;
 	unsigned int     sco_num;
 	unsigned int     le_num;