Bluetooth: hci_conn: remove extra line in hci_le_big_create_sync

Remove extra line setting the broadcast code parameter of the
hci_cp_le_create_big struct to 0. The broadcast code is copied
from the QoS struct.

Signed-off-by: Iulia Tanasescu <iulia.tanasescu@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>