bug#4446: remove ###autoload from ediff-hook.el

[Dan Nicolaescu]

Glenn Morris <rgm@gnu.org> writes:

  > Dan Nicolaescu wrote:
  > 
  > > The ###autoload in ediff-hook.el is not needed
  > [...]
  > > OK to remove the autoload line?
  > 
  > The last time this question was asked, the ediff maintainer asked for
  > it not to be removed:
  > 
  > http://lists.gnu.org/archive/html/emacs-devel/2008-03/msg00896.html

Hmm, I forgot about this.
But removing a single line in a file that hardly ever changes does not
seem like a bit maintenance burden.
On the other hand the autoload adds ~10KB to all emacs downloads, plus a
few symbols that are defined and never ever used (but need to be GCed
every single time for ALL users).