Be less verbose in the absence of real errors. We don't have to report
failed probes to the users, it's only confusing them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Andrey Gusev <ronne@list.ru>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: stable@kernel.org