Unwanted completion function

[Vladimir Sedach]

If you look at slime-contribs (the default list of contribs to load),
it is set to slime-fancy, which includes slime-c-p-c. So that is
where the hook to slime-completion-at-point-functions is being added.

You can either eval (slime-c-p-c-unload) after loading SLIME, or
customize slime-contribs to load only the contribs you want
(recommended by the manual).

--
Vladimir Sedach