fdisk: GiB vs GB

[John Spencer]

util-linux's fdisk displays harddisk size with the definition of GB used 
by HDD vendors, that is 1000*1000*1000, whereas busybox' fdisk displays 
them as "GiB", i.e. 1024*1024*1024.

i'm fine with either, however for consistency we should probably use the 
   definition used by util-linux or at least write "GiB" instead of "G" 
to make the difference clear.

example:

busybox:    Disk /dev/sdb: 5860533168 sectors, 2794G
util-linux: Disk /dev/sdb: 3000.6 GB, 3000592982016 bytes, 5860533168 
sectors