By Matt Hladik We’ve got our first surprising deal of the NBA trade deadline. The Dallas Mavericks have traded Kristaps Porzingis back east. Porzingis is heading to the Washington Wizards as part of a trade involving veteran guard Spencer Dinwiddie, according to reports. The move comes a little over three years after Dallas secured Porzingis in a trade with the New York Knicks. The sweet-shooting Latvian big man was acquired with the hope he would be a franchise cornerstone for the Mavs. However, while Porzingis averaged 20.0 points per game during his tenure in Dallas, injuries plagued him, a…