hwmon: (adt7475) Fix temperature fault flags

The logic of temperature fault flags is wrong, it shows faults when
there are none and vice versa. Fix it.

I can't believe this has been broken since the driver was added, 8
months ago, basically breaking temp1 and temp3, and nobody ever
complained.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Cc: Jordan Crouse <jordan@cosmicpenguin.net>