BlackBerry: properly clean up QFileDialog files

Task-number: QTBUG-34983

Change-Id: I1af5c6a9c43eba77394b11d31d1d223af8bc221f
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>

src/plugins/platforms/qnx/qqnxfilepicker.cpp

@@ -84,6 +84,9 @@ void QQnxFilePicker::open()
     if (m_invocationHandle)
         return;
 
+    // Clear any previous results
+    m_selectedFiles.clear();
+
     int errorCode = BPS_SUCCESS;
 
     errorCode = navigator_invoke_invocation_create(&m_invocationHandle);