Resolve some variable hiding warnings

(C4456: variable hides previous local declaration)

src/citra_qt/main.cpp

@@ -1454,7 +1454,6 @@ void GMainWindow::InstallCIA(QStringList filepaths) {
     progress_bar->setMaximum(INT_MAX);
 
     QtConcurrent::run([&, filepaths] {
-        QString current_path;
         Service::AM::InstallStatus status;
         const auto cia_progress = [&](std::size_t written, std::size_t total) {
             emit UpdateProgress(written, total);