Bluetooth: hidp: merge hidp_process_{ctrl,intr}_transmit()

Both hidp_process_ctrl_transmit() and hidp_process_intr_transmit() are
exactly the same apart from the transmit-queue and socket pointers.
Therefore, pass them as argument and merge both functions into one so we
avoid 25 lines of code-duplication.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>