hwmon: (ucd9000/ucd9200) Optimize array walk

Rewrite the loop walking the id array during probe. The new code is
better adapted to a null-terminated array, and is also clearer and
more efficient than the original.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Axel Lin <axel.lin@gmail.com>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>