Bluetooth: Use new header structures in l2cap_send_rr_or_rnr

struct l2cap_ctrl is now used, and the sframe is now sent directly
rather than depending on a separate call.

Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>