KdcDecoder::getInputBuffer(): correctly sanitize that we have whole bytes
KdcDecoder::getInputBuffer(): correctly sanitize that we have whole bytes

LebedevRI/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed