CVE-2023-34968: mdssvc: return a fake share path

CVE-2023-34968: mdssvc: return a fake share path

Instead of returning the real server-side absolute path of shares and search
results, return a fake absolute path replacing the path of the share with the
share name, iow for a share "test" with a server-side path of "/foo/bar", we
previously returned

  /foo/bar and
  /foo/bar/search/result

and now return

  /test and
  /test/search/result

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15388

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>