Revert "Only count successful nonces as hashrate in the knc driver." The original hashrate calculation is more correct, counting hashing completed notifications, not found shares, even if slightly inflated by hw errors in some cases. A perhaps better way to show effective hash rate is to present WU as a hash rate. If WU and hardware reported hash rate differs too much over a reasonable period of time then something is not right. This reverts commit 32ec3628219bfcbf1d964019302a9f420a7a9cab.