Everything indicates that he is not dreaming, exept for the symbol, but if is all a dream Quaid´s should never had dream with Melina before he goes to RECALL and that entire first escene doesn´t fit.
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 english is not my first languaje.
*who says the symbol is permanent. it could be as simple as an ink stamp and have simply washed off. so imho everything is real or as you say the first scene would make absolutely no sense.
