I've used the DHT11 with almost the same fix and behavior (some error eventually) in Galileo. Having said that, I think you should post Edison questions in the Edison forum:
Please try the attached code, I've used it with DHT11 in Galileo, but DHT22 seems to be "just" a better version of the DHT11 so I hopefully expect the sketch works. Suggested usage:
b) Connect DHT data pin to pin3
Take into account that Galileo (and I think Edison) does not seem to be well suited for DHT usage. There are lots of threads explaining why.
You could also try the examples mentioned in the book Exploring Edison (http://www.i-programmer.info/programming/hardware/8198-exploring-edison-meet-edison.html): http://www.i-programmer.info/programming/hardware/8198-exploring-edison-meet-edison.html):
They offer an approach with mraa which might also interest you.