Print transfer times for read, write, & overall independently.

Round up calculated values for iops and average time per io to avoid a
shifting display if there are 1000+ (or even 10000+) iops, or if an
average time per io column is 1000+ ms.

Reviewed by: ken
MFC after: 1 week
Sponsored by: Spectra Logic
MFSpectraBSD: 1089947 on 2014/09/26

		1093625 on 2014/09/29
		1093650 on 2014/09/29
		1095662 on 2014/10/09