Debugger: Fixes crash selecting a filter search with new search button

Fixes crash issues when trying to use a search comparison that requires prior results with the New Search button instead of Filter Search.

pcsx2-qt/Debugger/MemorySearchWidget.cpp

@@ -556,6 +556,15 @@ void MemorySearchWidget::onSearchButtonClicked()
 			return;
 	}
 
+	if (!isFilterSearch && (searchComparison == SearchComparison::Changed || searchComparison == SearchComparison::ChangedBy
+		|| searchComparison == SearchComparison::Decreased || searchComparison == SearchComparison::DecreasedBy
+		|| searchComparison == SearchComparison::Increased || searchComparison == SearchComparison::IncreasedBy
+		|| searchComparison == SearchComparison::NotChanged))
+	{
+		QMessageBox::critical(this, tr("Debugger"), tr("This search comparison can only be used with filter searches."));
+		return;
+	}
+
 	QFutureWatcher<std::vector<SearchResult>>* workerWatcher = new QFutureWatcher<std::vector<SearchResult>>();
 	auto onSearchFinished = [this, workerWatcher] {
 		m_ui.btnSearch->setDisabled(false);