Staging: media: lirc: Use USB API functions rather than constants

Introduce use of function usb_endpoint_is_int_in() and
usb_endpoint_is_int_out(). Also remove the variables
ep_dir and ep_type as they are not used anymore.

Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>