fixed incorrect device id in multi_gpu sample (checked both multi GPU samples work correctly with new multi GPU API)
fixed incorrect device id in multi_gpu sample (checked both multi GPU samples work correctly with new multi GPU API)

opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv