Use local style for paths when formatting error messages from the
'svn diff --old A --new B' commands.  Follow-up to r1310291.

* subversion/libsvn_client/diff_local.c
  (svn_client__arbitrary_nodes_diff): Use local style for paths when formatting
    the "not the same node kind" and "not a file or directory" messages.

Patch by: Evgeny Kotkov <evgeny.kotkov{_AT_}visualsvn.com>