fix confusion-matrix xlabel typo
Signed-off-by: ZhuGeRoastedFish <77224640+ZhuGeRoastedFish@users.noreply.github.com>
Signed-off-by: ZhuGeRoastedFish <77224640+ZhuGeRoastedFish@users.noreply.github.com>
Co-authored-by: Glenn Jocher <glenn.jocher@ultralytics.com>