Gets the output name from the IOTHUB_MESSAGE_HANDLE. No new memory is allocated, the caller is not responsible for freeing the memory. The memory is valid until IoTHubMessage_Destroy is called on the message.
const char* IoTHubMessage_GetOutputName(IOTHUB_MESSAGE_HANDLE iotHubMessageHandle);
iotHubMessageHandleHandle to the message.
A const char* pointing to the Output Id.