Fix bug whereby saving files hung in VC hook.

Saving a buffer visiting a file under SVN control would hang if the
remote repository were unreachable, because the VC hooks tried to run
"svn status -u" on the file, where the "-u" tells svn to get update
information from the remote repository.
http://lists.gnu.org/archive/html/emacs-devel/2014-12/msg00174.html

* vc/vc-svn.el (vc-svn-state): Remove optional `localp' argument
  and always pass "-v" to "svn status", never "-u".