staging: r8188eu: remove write-only fields from struct rtl_ps

The fields pre_cca_state, cur_cca_state and rssi_val_min of struct
rtl_ps are set but never used. Remove them.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20211228101120.9120-6-straube.linux@gmail.com


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