why did walt call the dea at the end?
After talking to Walt Jr., he was just going to give up and turn himself in. Then, while he was sitting at the bar, he saw his former partners from Gray Matter on Charlie Rose saying that he had nothing to do with the start of their company other than the name, which infuriated Walter and inspired him to finish what he started. He doesn't want to be sweet and kind and everyone's doormat. He's Heisenberg now, and he wants to be recognized for his work, regardless of the fact that it's a criminal empire.