bug#11999: 24.1.50; New Info file suffix ".info" breaks `Info-find-node-2'

[Drew Adams]

> > The code does exactly the same thing, step by step.  But when
> > `info-insert-file-contents' is called in the 7/16 build it 
> > returns nil instead of t
> 
> info-insert-file-contents doesn't return a boolean (in fact it doesn't
> return any useful value at all).

Look at the two backtraces.  Contrast their first lines.

It should be clear that I meant `info-file-exists-p', not
`info-insert-file-contents'.

This is the problem - there is no such file:

  info-file-exists-p("c:/Emacs-24-2012-07-16/info/emacs")