Small optimization for FullyConnected::Forward, FullyConnected::Backward
Small optimization for FullyConnected::Forward, FullyConnected::Backward

Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

stweil/tesseract,stweil/tesseract,stweil/tesseract,stweil/tesseract,stweil/tesseract