Doesn't change much. Labour was pretty much doomed after the Winter of Discontent and the day after the confidence vote the Liberal's David Alton won the Liverpool Edge Hill by-election that, if Alton had gotten to take his seat, would have further weakened the Government's position. Although he could have hung on until November by all accounts Callaghan was fed up with the strain of trying to keep the Government going and was planning on going to the country sooner rather than later. Given that the polls at the time showed clear Tory leads Thatcher's position was secure, she might have had to wait a bit longer but she was in all likelihood going to become PM later that year.