cooling-type: Use lookupAndCallMethod

Have phosphor-cooling-type fail with a DBusMethodError exception when a
failure occurs on updating inventory.

Resolves: openbmc/openbmc#2628

Tested:
    Cooling type properties still set correctly

Change-Id: Ia7e3379fc7d75c70e9c71d4f940f9da84b9f5774
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
3 files changed