message: Rename nValue and nValueToSelect
  nValue is the sum of the intended recipient amounts, so name it that for
  clarity.
  nValueToSelect is the coin selection target value, so name it
  selection_target for clarity.
diff: @@ -580,18 +580,18 @@ bool CWallet::CreateTransactionInternal(
  {
  AssertLockHeld(cs_wallet);
  - CAmount nValue = 0;
  + CAmount recipients_sum = 0;
  const OutputType change_type = TransactionChangeType(coin_control.m_change_type ? *coin_control.m_change_type : m_default_change_type, vecSend);
  ReserveDestination reservedest(this, change_type);
  unsigned int nSubtractFeeFromAmount = 0;
  for (const auto& recipient : vecSend)
  {
  - if (nValue < 0 || recipient.nAmount < 0)
  + if (recipients_sum < 0 || recipient.nAmount < 0)
  {
  error = _("Transaction amounts must not be negative");
  return false;
  }
  - nValue += recipient.nAmount;
  + recipients_sum += recipient.nAmount;
  if (recipient.fSubtractFeeFromAmount)
  nSubtractFeeFromAmount++;
  @@ -709,12 +709,12 @@ bool CWallet::CreateTransactionInternal(
  // Include the fees for things that aren't inputs, excluding the change output
  const CAmount not_input_fees = coin_selection_params.m_effective_feerate.GetFee(coin_selection_params.tx_noinputs_size);
  - CAmount nValueToSelect = nValue + not_input_fees;
  + CAmount selection_target = recipients_sum + not_input_fees;
  // Choose coins to use
  CAmount inputs_sum = 0;
  setCoins.clear();
  - if (!SelectCoins(vAvailableCoins, /* nTargetValue */ nValueToSelect, setCoins, inputs_sum, coin_control, coin_selection_params))
  + if (!SelectCoins(vAvailableCoins, /* nTargetValue */ selection_target, setCoins, inputs_sum, coin_control, coin_selection_params))
  {
  error = _("Insufficient funds");
  return false;
  @@ -722,7 +722,7 @@ bool CWallet::CreateTransactionInternal(
  // Always make a change output
  // We will reduce the fee from this change output later, and remove the output if it is too small.
  - const CAmount change_and_fee = inputs_sum - nValue;
  + const CAmount change_and_fee = inputs_sum - recipients_sum;
  assert(change_and_fee >= 0);
  CTxOut newTxOut(change_and_fee, scriptChange);
  