Currently, kernel doesn't print the name of root device if it is
network device (like: root on tlp1).  I guess it is probably we print
the remote file system later.  But I think printing the name of root
device also is useful, especially if system has multiple interface.

So, I'd like to change to print it.

Comments or objection?

BTW, while I'm reading the code around there, I found that if kernel
is configured to dump to `none', new setting with RB_ASKNAME doesn't
take effect.  I guess this is a bug and will fix it.

enami.