staging: rtl8188eu: remove unused variable ratelen

After the removal of cckrates_included() and cckrates_only_included()
from rtw_wlan_util.c the variable/parameter 'ratelen' is unused now.
Remove it from update_wireless_mode() and judge_network_type().

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20200929062847.23985-7-straube.linux@gmail.com


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