Title: diskstat: Only excluding multipath members when infos for multipath devices are available
Level: 1
Component: checks
Compatible: compat
Version: 1.2.7i3
Date: 1438848951
Class: fix

Werk #1831 made the discovery exclude member disks of multipath devices. Only do this when
diskstat has information for the multipath devices. Otherwise there will be no Disk IO information
at all for these devices.
