Tramp docstring

[Luc Teirlinck]

As I said before, `verify-visited-file-modtime' itself takes care of
the cases where `visited-file-modtime' returns 0 or the buffer is not
visiting a file, so `tramp-handle-verify-visited-file-modtime' does
not need to.  However, this means that
`tramp-handle-verify-visited-file-modtime' can not be called directly,
unless the caller first takes care of those two cases.  That probably
is no problem, but these facts should be at least pointed out as a
comment.  To be sure that people are not tempted to call the function
directly after doing C-h f, I prefer to put it in the docstring.  But
a comment would be OK too.

What about the following new docstring?

  "Like `verify-visited-file-modtime' for tramp files.
At the time this function is called, we already know that the buffer
is visiting a file and that `visited-file-modtime' does not return 0.
Do not call this function directly, unless those two cases are already
taken care of."

Sincerely,

Luc.