Bug#479735: Bug#479056: grub-probe also fails with cciss

[Roland Dreier]

 > > (The "Duplicated entry" error seems to be an unrelated buglet caused by
 > > grub-probe not discarding the previous map[] contents when regenerating
 > > device.map)
 > 
 > Ugh.  That deserves a new bug I think.  Could you file it as a reminder?

OK, will file later.

 > Ok, here's a complete patch.  Can you confirm this one is good?

Yes, this appears to work perfectly, thanks.