vc-mode nit: C-x v v doesn't add a file in a subdir

[Jim Meyering]

I was surprised by this:

  $ git-init
  Initialized empty Git repository in .git/
  $ mkdir c; echo a > c/f; emacs c/f

then I typed C-x v v, and got this:

  vc-deduce-fileset: No fileset is available here.