Qt: Fix return code confusion in AchievementLoginDialog

We were passing the wrong code to QDialog::done(). Qt defines 0 as Rejected
and 1 as Accepted. This had no practical impact because callers were also
using the inverted logic. The accepted()/rejected() signals were emitted
incorrectly but nothing is using them at the moment.

Still, to prevent further issues and improve code readability, flip the logic
and prefer accept()/reject() over done().

src/duckstation-qt/achievementlogindialog.cpp

@@ -65,7 +65,7 @@ void AchievementLoginDialog::cancelClicked()
     });
   }
 
-  done(1);
+  reject();
 }
 
 void AchievementLoginDialog::processLoginResult(bool result, const QString& message)
@@ -119,7 +119,7 @@ void AchievementLoginDialog::processLoginResult(bool result, const QString& mess
     }
   }
 
-  done(0);
+  accept();
 }
 
 void AchievementLoginDialog::connectUi()

src/duckstation-qt/achievementsettingswidget.cpp

@@ -221,7 +221,7 @@ void AchievementSettingsWidget::onLoginLogoutPressed()
 
   AchievementLoginDialog login(this, Achievements::LoginRequestReason::UserInitiated);
   int res = login.exec();
-  if (res != 0)
+  if (res == QDialog::Rejected)
     return;
 
   updateLoginState();

src/duckstation-qt/audiosettingswidget.cpp

@@ -325,7 +325,7 @@ void AudioSettingsWidget::onStretchSettingsClicked()
                                     std::nullopt :
                                     std::optional<bool>(AudioStreamParameters::DEFAULT_STRETCH_USE_AA_FILTER));
 
-    dlg.done(0);
+    dlg.reject();
 
     QMetaObject::invokeMethod(this, &AudioSettingsWidget::onStretchSettingsClicked, Qt::QueuedConnection);
   });

src/duckstation-qt/coverdownloaddialog.cpp

@@ -78,7 +78,7 @@ void CoverDownloadDialog::onCloseClicked()
   if (m_thread)
     cancelThread();
 
-  done(0);
+  reject();
 }
 
 void CoverDownloadDialog::updateEnabled()

src/duckstation-qt/gamecheatsettingswidget.cpp

@@ -926,12 +926,12 @@ void CheatCodeEditorDialog::saveClicked()
                           tr("Failed to save cheat code:\n%1").arg(QString::fromStdString(error.GetDescription())));
   }
 
-  done(1);
+  accept();
 }
 
 void CheatCodeEditorDialog::cancelClicked()
 {
-  done(0);
+  reject();
 }
 
 void CheatCodeEditorDialog::onOptionTypeChanged(int index)

src/duckstation-qt/inputbindingdialog.cpp

@@ -30,7 +30,7 @@ InputBindingDialog::InputBindingDialog(SettingsInterface* sif, InputBindingInfo:
   connect(m_ui.addBinding, &QPushButton::clicked, this, &InputBindingDialog::onAddBindingButtonClicked);
   connect(m_ui.removeBinding, &QPushButton::clicked, this, &InputBindingDialog::onRemoveBindingButtonClicked);
   connect(m_ui.clearBindings, &QPushButton::clicked, this, &InputBindingDialog::onClearBindingsButtonClicked);
-  connect(m_ui.buttonBox, &QDialogButtonBox::rejected, [this]() { done(0); });
+  connect(m_ui.buttonBox, &QDialogButtonBox::rejected, [this]() { reject(); });
   updateList();
 
   // Only show the sensitivity controls for binds where it's applicable.

src/duckstation-qt/selectdiscdialog.cpp

@@ -38,7 +38,7 @@ void SelectDiscDialog::onListItemActivated(const QTreeWidgetItem* item)
     return;
 
   m_selected_path = item->data(0, Qt::UserRole).toString().toStdString();
-  done(1);
+  accept();
 }
 
 void SelectDiscDialog::updateStartEnabled()
@@ -53,12 +53,12 @@ void SelectDiscDialog::updateStartEnabled()
 
 void SelectDiscDialog::onSelectClicked()
 {
-  done(1);
+  accept();
 }
 
 void SelectDiscDialog::onCancelClicked()
 {
-  done(0);
+  reject();
 }
 
 void SelectDiscDialog::populateList(const std::string& disc_set_name)

src/duckstation-qt/setupwizarddialog.cpp

@@ -698,7 +698,7 @@ void SetupWizardDialog::onAchievementsLoginLogoutClicked()
 
   AchievementLoginDialog login(this, Achievements::LoginRequestReason::UserInitiated);
   int res = login.exec();
-  if (res != 0)
+  if (res == QDialog::Rejected)
     return;
 
   updateAchievementsEnableState();