[utils] Fixed manual checksum calculation for odd sized packets
[utils] Fixed manual checksum calculation for odd sized packets

emmericp/MoonGen,NetronomeMoongen/MoonGen,atheurer/MoonGen,NetronomeMoongen/MoonGen,atheurer/MoonGen,scholzd/MoonGen,emmericp/MoonGen,dschoeffm/MoonGen,gallenmu/MoonGen,gallenmu/MoonGen,gallenmu/MoonGen,atheurer/MoonGen,gallenmu/MoonGen,gallenmu/MoonGen,scholzd/MoonGen,NetronomeMoongen/MoonGen,bmichalo/MoonGen,gallenmu/MoonGen,bmichalo/MoonGen,dschoeffm/MoonGen,bmichalo/MoonGen,gallenmu/MoonGen,emmericp/MoonGen,gallenmu/MoonGen,scholzd/MoonGen,dschoeffm/MoonGen,bmichalo/MoonGen