I don't think it is a whitewash. From what I have read (which admittedly is not a great deal as yet), it is pretty scathing of Blair.
(From the BBC website, very high level
Tony Blair overstated the threat posed by Saddam Hussein, sent ill-prepared troops into battle and had "wholly inadequate" plans for the aftermath, the UK's Iraq War inquiry has said.
Chairman Sir John Chilcot said the 2003 invasion was not the "last resort" action presented to MPs and the public.
There was no "imminent threat" from Saddam - and the intelligence case was "not justified", he said.)
Those are pretty serious findings. The question is whether anything can be done about them. There is maybe an issue with people's expectations of the inquiry. Anyone who was expecting Tony Blair to be denounced as taking the country into an illegal war was always going to be disappointed as that determination was not within Chilcot's remit.
From the Inquiry website, the terms of reference are described as :
"...It will consider the period from the summer of 2001 to the end of July 2009, embracing the run-up to the conflict in Iraq, including the way decisions were made and actions taken, to establish, as accurately as possible, what happened and to identify the lessons that can be learned. Those lessons will help ensure that, if we face similar situations in future, the government of the day is best equipped to respond to those situations in the most effective manner in the best interests of the country."
Nothing about deciding the legality of the decision to go to war in the first place.
It may open the way for some civil actions to be taken - although I imagine that would take years to complete and involve significant costs.
My comment is not on whether the war was right or wrong (my sense is that it was wrong) but rather that Blair is far, far from being exonerated - quite the opposite.