Kevin Wayne is one of the co-authors of the book, but the copyright listing is "Copyright 2011 Pearson Education, Inc." and there does not appear to be anything in the book that says that the code is GPL licensed.

Presumably Kevin Wayne was given the right to license the code as GPL, but that fact didn't get included in the text of the book, and the f*cking, stupid copyright bot Pearson uses didn't get the memo.