Bug report in defective-component-counter smart contract

* ComputeTotal function does not satisfy its specification
https://github.com/Azure-Samples/blockchain/blob/1b712d6d05cca8da17bdd1894de8c3d25905685d/blockchain-workbench/application-and-smart-contract-samples/defective-component-counter/ethereum/DefectiveComponentCounter.sol#L24-L39

As documented by its following specification, computeTotal funtion can only be called once. However, in the contract implementation, there is no such restriction.
https://github.com/Azure-Samples/blockchain/blob/1b712d6d05cca8da17bdd1894de8c3d25905685d/blockchain-workbench/application-and-smart-contract-samples/defective-component-counter/ethereum/DefectiveComponentCounter.json#L73-L99

* Bug repair
We can fix such bug using the following statement.
```solidity
// call this function to send a request
function ComputeTotal() public
{
// Fix
if (State != StateType.Create)
{
revert();
}
...
```