The Initialization section contains two errors:
1. bt_enable() is the public API for initializing the stack, not
bt_init().
2. When bt_enable() is passed a function pointer, initialization
happens asynchronously, not synchronously.
Fix these.
Change-Id: If02a6d6fe82f546b5cb6f9fdf76c6641baa6cac8
Signed-off-by: Marti Bolivar <marti.bolivar@linaro.org>