Replace incorrectly named comment with func #15979

This code was previously part of ConnectBlock() hence the log string, at some point it was moved to WriteUndoDataForBlock(). It seems sensible to me to use the magic constant func.

I'd also like to update several other places where func has been used intermittently. It's helpful to make logging code more dynamic, but also remove logging code from grep results when searching on function name. I was actually grepping ConnectBlock() and saw this misplaced result, ConnectBlock() itself has several logging lines that both use and do not use func, it's somewhat piecemeal.

I'm not entirely sure whether use of func falls under the category of style but the change in this pull request changes a incorrectly labelled log entry.

utACK ad3677477aadf5813bbe685333c757e8a4fbd493

FWIW, these could be candidates for the same __func__ treatment:

$ git grep 'LogPrint.*("[A-Z][A-Za-z:]*: ' -- "*.cpp" "*.h" | egrep -v '"(WARNING|Warning|HTTP|Error|Prune|UPnP|GUI|LOCKCONTENTION|Locker|ERROR|Keys): '
src/netbase.cpp:        LogPrintf("ConnectSocketDirectly: Setting socket to non-blocking failed, error %s\n", NetworkErrorString(WSAGetLastError()));
src/txmempool.cpp:    LogPrintf("PrioritiseTransaction: %s feerate += %s\n", hash.ToString(), FormatMoney(nFeeDelta));
src/validation.cpp:            LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n", FormatStateMessage(state));
src/validation.cpp:            LogPrintf("RewindBlockIndex: unable to flush state to disk (%s)\n", FormatStateMessage(state));
src/wallet/db.cpp:        LogPrintf("BerkeleyEnvironment::Close: Error %d closing database environment: %s\n", ret, DbEnv::strerror(ret));
src/wallet/db.cpp:    LogPrintf("BerkeleyEnvironment::Open: LogDir=%s ErrorFile=%s\n", pathLogDir.string(), pathErrorFile.string());
src/wallet/db.cpp:        LogPrintf("BerkeleyEnvironment::Open: Error %d opening database environment: %s\n", ret, DbEnv::strerror(ret));
src/wallet/db.cpp:            LogPrintf("BerkeleyEnvironment::Open: Error %d closing failed database environment: %s\n", ret2, DbEnv::strerror(ret2));
src/wallet/db.cpp:        LogPrintf("BerkeleyEnvironment::Salvage: Database salvage found errors, all data may not be recoverable.\n");
src/wallet/db.cpp:            LogPrintf("BerkeleyEnvironment::Salvage: Rerun with aggressive mode to ignore errors and continue.\n");
src/wallet/db.cpp:        LogPrintf("BerkeleyEnvironment::Salvage: Database salvage failed with result %d.\n", result);
src/wallet/db.cpp:                LogPrintf("BerkeleyEnvironment::Salvage: WARNING: Number of keys in data does not match number of values.\n");
src/wallet/db.cpp:        LogPrintf("BerkeleyEnvironment::Salvage: WARNING: Unexpected end of file while reading salvage output.\n");
src/wallet/db.cpp:                LogPrintf("BerkeleyBatch::Rewrite: Rewriting %s...\n", strFile);
src/wallet/db.cpp:                        LogPrintf("BerkeleyBatch::Rewrite: Can't create database file %s\n", strFileRes);
src/wallet/db.cpp:                    LogPrintf("BerkeleyBatch::Rewrite: Failed to rewrite database file %s\n", strFileRes);
src/wallet/wallet.cpp:            pwallet->WalletLogPrintf("CWalletTx::GetAmounts: Unknown transaction type found, txid %s\n"

@practicalswift I agree. There are also cases that apply without LogPrint when error() is returned with a log message. I'll work through the ones you listed above and any additional ones related to error and create a new pull request including the change here. I expect changing all these entries will generate a few pull request conflicts.

Going to close this in favour of #15981. If these are going to be changed, might as well do them all at once.