[PATCH] Properly format the error message during unintended switches

Hi,

Currently the 'svn switch' command attempts to protect users from unintended
switches by performing the ancestry check [1]. However, the error message for
the unintended switch scenario appears to be incorrect. On my Windows machine,
'svn switch "^/" "C:\Projects\Subversion"' produces the following messages:

[[[
svn: E195012: Path '.' does not share common version control ancestry with the
requested switch location. Use --ignore-ancestry to disable this check.
svn: E195012: 'http://svn.apache.org/repos/asf' shares no common ancestry with
'C:/Projects'
]]]

The path and the separator style in the second message both appear to be
incorrect. I've attached a patch that fixes this problem (we should use
svn_dirent_local_style instead of svn_dirent_dirname).

[1] http://subversion.tigris.org/issues/show_bug.cgi?id=3848

Thanks and regards,
Evgeny Kotkov