Qt: Add exported packet files to the recent files

Update the recent files list when exporting specified packets to file.

Change-Id: I4e7dd7f943aa99ab9d5f3fd88444d730434970e9
Reviewed-on: https://code.wireshark.org/review/19818
Reviewed-by: Stig Bjørlykke <stig@bjorlykke.org>

ui/qt/main_window.cpp

@@ -1524,6 +1524,8 @@ void MainWindow::exportSelectedPackets() {
                any packets that no longer have comments. */
             if (discard_comments)
                 packet_list_queue_draw();
+            /* Add this filename to the list of recent files in the "Recent Files" submenu */
+            add_menu_recent_capture_file(file_name.toUtf8().constData());
             return;
 
         case CF_WRITE_ERROR: