yuzu/main: Remove unnecessary string concatenation in OnTransferableShaderCacheOpenFile()

We can just make the trailing portion of the string part of the
formatting, getting rid of the need to make another temporary string.

src/yuzu/main.cpp

@@ -1094,7 +1094,7 @@ void GMainWindow::OnTransferableShaderCacheOpenFile(u64 program_id) {
 
     const QString transferable_shader_cache_file_path =
         tranferable_shader_cache_folder_path + DIR_SEP +
-        QString::fromStdString(fmt::format("{:016X}", program_id)) + ".bin";
+        QString::fromStdString(fmt::format("{:016X}.bin", program_id));
 
     if (!QFile::exists(transferable_shader_cache_file_path)) {
         QMessageBox::warning(this, tr("Error Opening %1 File").arg(open_target),