staging: wlan-ng: remove unused field from struct hfa384x_usbctlx

The variant field in struct hfa384x_usbctlx is not referenced anywhere
in the driver, so remove it.

Signed-off-by: Tim Collier <osdevtc@gmail.com>
Link: https://lore.kernel.org/r/20191025084126.9181-6-osdevtc@gmail.com


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