Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_add_adv_monitor()

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Avoid use-after-free in dbg for hci_add_adv_monitor() KSAN reports use-after-free in hci_add_adv_monitor(). While adding an adv monitor, hci_add_adv_monitor() calls -> msft_add_monitor_pattern() calls -> msft_add_monitor_sync() calls -> msft_le_monitor_advertisement_cb() calls in an error case -> hci_free_adv_monitor() which frees the *moniter. This is referenced by bt_dev_dbg() in hci_add_adv_monitor(). Fix the bt_dev_dbg() by using handle instead of monitor->handle.