Werk #5708: df: Fix incorrect values being reported on devices with btrfs

KomponenteChecks & Agents
Titeldf: Fix incorrect values being reported on devices with btrfs
Datum2018-01-28 11:53:18
Checkmk EditionCheckmk Raw Edition (CRE)
Checkmk Version1.5.0i3
LevelProminent Change
KlasseBug Fix
KompatibilitätKompatibel - benötigt kein manuelles Eingreifen

This fixes a bug introduced with Werk #4806.