Everything indicates that he is not dreaming, exeptexcept for the symbol, but if isit's all a dream Quaid´s should never had dream withwould have dreamt about Melina before he goes to RECALL and that entire first escenescene doesn´t fitmake sense.
Now assuming that is all real there is no explanation for the symbol.
So in my opinion it has the ending wrong.
Sorry for the misspell but englishThere is not my first languaje.
*who saysno reference that the symbol is permanent. it could be as simple as an ink stamp and have simply washed off.can be erased easily, so imho everything is real or as you say the first scene would make absolutely no sense.