Bluetooth: hci_ldisc: Fix tty_set_termios() return value assumptions

tty_set_termios() never returns anything else than 0. Make the debug
prints to look directly into the new termios instead to check CRTSCTS
state.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>