staging: r8188eu: Remove no more used functions and variables

Remove the functions and variables from rtw_security.c that are no more
necessary since the patch that replaces getcrc32() with crc32_le().

Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20210730103716.27210-3-fmdefrancesco@gmail.com


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