staging: r8188: antSumRSSI is set but not used

antSumRSSI in struct fast_ant_train is set but not used. Remove it.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211218120423.29906-6-martin@kaiser.cx


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