staging: rtl8192e: Remove unimplemented iwpriv handlers

Remove the following private variables:
- force_mic_error - changes force_mic_error that is not used
- radio - changes sw_radio_on that is not used
- adhoc_peer_list - unimplemented
- firm_ver - unimplemented

Signed-off-by: Mateusz Kulikowski <mateusz.kulikowski@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>