The process only takes the pure water out of the salty water, leaving a heavier concentration of salt in the water that is left (called "brine" in the article I posted upthread). The brine is then pumped out to sea to mix in with the seawater.
It has yet to be seen if it can be successfully mixed in with the seawater with no ill effect over an extended period of time (unintended consequences and all that).
The net amount of salt in the ocean would be... the same.