staging: r8188eu: remove SetHalDefVar8188EUsb()

In SetHalDefVar8188EUsb() there is only the case HAL_DEF_DBG_DM_FUNC.
Move its functionality to a new static function in ioctl_linux.c and
remove SetHalDefVar8188EUsb(). This is part of the ongoing effort to
get rid of the unwanted hal layer.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220408124615.3687-1-straube.linux@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>