SdoWrite在写入sdoSubIndex=0，且只有一个值需要写入时的bug

[m819895641]

在soem_wrapper.c的SdoWrite函数中，如果sdoSubIndex == 0，且datasetCount==1，那此时只写入了&null，然后直接return了
else // legacy access
{
int offset = 0;

    if (sdoSubIndex == 0) // sdoSubIndex == 0
    {
        returnValue += ecx_SDOwrite(context, slaveIndex, sdoIndex, 0, FALSE, byteCountSet[0], &null, timeout);
        offset += byteCountSet[0];

        for (uint32 i = 1; i < datasetCount; i++)
        {
            returnValue += ecx_SDOwrite(context, slaveIndex, sdoIndex, i, FALSE, byteCountSet[i], &dataset[offset], timeout);
            offset += byteCountSet[i];
        }

        if (datasetCount > 1)
        {
            returnValue += ecx_SDOwrite(context, slaveIndex, sdoIndex, 0, FALSE, byteCountSet[0], &dataset[0], timeout);

            return returnValue == datasetCount + 1 ? 1 : 0;
        }
    }
    else // random access
    {
        for (uint32 i = 0; i < datasetCount; i++)
        {
            returnValue += ecx_SDOwrite(context, slaveIndex, sdoIndex, i + sdoSubIndex, FALSE, byteCountSet[i], &dataset[i], timeout);
        }
    }

    return returnValue == datasetCount ? 1 : 0;
}