bug#5476: 23.1.91; bookmark open info node in fundamental mode

[Leo]

1. Emacs -q
2. C-h i m d emacs RET
3. C-x r m RET
4. C-x r b and select the bookmark in step 3 (It is 'top' in my case)

The info will be opened in fundamental mode. Tested with bookmark.el
from the devel repo.

In GNU Emacs 23.1.91.2 (i386-apple-darwin9.8.0, Carbon Version 1.6.0 AppKit 
949.54)
 of 2010-01-01 on victoria.local
Windowing system distributor `Apple Inc.', version 10.5.8
configured using `configure  '--with-mac' 
'--prefix=/usr/local/opensource/emacs''