staging: r8188eu: remove c2h_handler field from struct hal_ops

staging: r8188eu: remove c2h_handler field from struct hal_ops

Remove c2h_handler function pointer field from struct hal_ops in
include/hal_intf.h, as it is never set in this driver, and remove
the check for a non-NULL value in the rtw_hal_c2h_handler wrapper
function in hal/hal_intf.c as well. As the function always returns
_FAIL anyway, just modify it to do this unconditionally.

The motivation for removing this field is that it is more code from
the unwanted HAL layer that can be stripped out.

Acked-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Acked-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210829234541.946-2-phil@philpotter.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>