#137 IEEESNap class returning wrong oui

[Oliver]

IEEESnap.oui() function returns on a CDP packet 0xc20, where the real oui should 0xc. I assume the 0x20 is added because the following pid field is 0x2000. Most likely a fix could be like this:

@Field(offset = 0, length = 24, format = "%x")
public long oui() {
    // return getUInt(0) & 0x00FFFFFF;
    return (getUInt(0) >> 8);
}