It seems that libsensors treats -EIO as a special non-recoverable
failure when it tries to read the temperature while the firmware is
not running. To solve that, change the error code to a milder
-ENODATA.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=196941
Fixes: c221daf219 ("iwlwifi: mvm: add registration to thermal zone")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>