Bluetooth: Split sending for HCI raw and control sockets

The sending functions for HCI raw and control sockets have nothing in
common except that they iterate over the socket list. Split them into
two so they can do their job more efficient. In addition the code becomes
more readable.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>