Bingo...  edd_devices[] was too short.  When we keep more than 6
signatures, it overruns the end.  Also, I rewrote edd_num_devices to be
clearer about its goal. 

This patch is necessary even after the last edd.S patch was reverted.

Thanks to Christian Kujau for testing and narrowing it down enough to
debug this. 

It still doesn't explain why Christian's BIOS reports more devices than
he has, that's still up in the air, so don't re-apply the edd.S patch
just reverted. 
Signed-off-by: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>