message: [Qt] small cleanup of coincontroldialog
  use a little more Qt-style
  check for NULL pointers first and return in updateView()
  small space and formating changes
diff: @@ -413,7 +413,8 @@ QString CoinControlDialog::getPriorityLabel(double dPriority)
  void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
  {
  - if (!model) return;
  + if (!model)
  + return;
  // nPayAmount
  qint64 nPayAmount = 0;
  @@ -626,6 +627,9 @@ void CoinControlDialog::updateLabels(WalletModel *model, QDialog* dialog)
  void CoinControlDialog::updateView()
  {
  + if (!model || !model->getOptionsModel() || !model->getAddressTableModel())
  + return;
  +
  bool treeMode = ui->radioTreeMode->isChecked();
  ui->treeWidget->clear();
  @@ -634,9 +638,7 @@ void CoinControlDialog::updateView()
  QFlags<Qt::ItemFlag> flgCheckbox = Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsUserCheckable;
  QFlags<Qt::ItemFlag> flgTristate = Qt::ItemIsSelectable | Qt::ItemIsEnabled | Qt::ItemIsUserCheckable | Qt::ItemIsTristate;
  - int nDisplayUnit = BitcoinUnits::BTC;
  - if (model && model->getOptionsModel())
  - nDisplayUnit = model->getOptionsModel()->getDisplayUnit();
  + int nDisplayUnit = model->getOptionsModel()->getDisplayUnit();
  map<QString, vector<COutput> > mapCoins;
  model->listCoins(mapCoins);
  @@ -644,11 +646,10 @@ void CoinControlDialog::updateView()
  BOOST_FOREACH(PAIRTYPE(QString, vector<COutput>) coins, mapCoins)
  {
  QTreeWidgetItem *itemWalletAddress = new QTreeWidgetItem();
  + itemWalletAddress->setCheckState(COLUMN_CHECKBOX, Qt::Unchecked);
  QString sWalletAddress = coins.first;
  - QString sWalletLabel = "";
  - if (model->getAddressTableModel())
  - sWalletLabel = model->getAddressTableModel()->labelForAddress(sWalletAddress);
  - if (sWalletLabel.length() == 0)
  + QString sWalletLabel = model->getAddressTableModel()->labelForAddress(sWalletAddress);
  + if (sWalletLabel.isEmpty())
  sWalletLabel = tr("(no label)");
  if (treeMode)
  @@ -711,10 +712,8 @@ void CoinControlDialog::updateView()
  }
  else if (!treeMode)
  {
  - QString sLabel = "";
  - if (model->getAddressTableModel())
  - sLabel = model->getAddressTableModel()->labelForAddress(sAddress);
  - if (sLabel.length() == 0)
  + QString sLabel = model->getAddressTableModel()->labelForAddress(sAddress);
  + if (sLabel.isEmpty())
  sLabel = tr("(no label)");
  itemOutput->setText(COLUMN_LABEL, sLabel);
  }
  