Bluetooth: Remove extra l2cap_state_change(BT_CONNECTED)

This is already performed inside l2cap_chan_ready(), so we don't need it
here again.

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Acked-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>