LUDOC-412 misc: Update byte prefixes to use IEC

LUDOC-412 misc: Update byte prefixes to use IEC

This patch fixes binary prefixes used when referencing
storage size to the IEC definitions:
1024    Ki 	kibi
1024^2  Mi 	mebi
1024^3  Gi 	gibi
1024^4  Ti 	tebi
1024^5 	Pi 	pebi
1024^6 	Ei 	exbi
1024^7 	Zi 	zebi
1024^8 	Yi 	yobi

Signed-off-by: Joseph Gmitter <jgmitter@whamcloud.com>
Change-Id: I3fac1dc28e96c34d286f9b14e8cd2b46acb87f53
Reviewed-on: https://review.whamcloud.com/33075
Tested-by: Jenkins
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>