sensorhandler: Fix uninitialized reads
sensorhandler: Fix uninitialized reads

The response struct in GetSensorThresholdsResponse was not initialized
and has arbitrary data leftover from the stack. Some values like upper
and lower non-recoverable never get initialized and end up with
garbage data being reported.

Change-Id: I766f8daeb60c1ebc987cff6a24f8d8d78d64ffdd
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/phosphor-host-ipmid,openbmc/phosphor-host-ipmid,openbmc/phosphor-host-ipmid