hwmon: Fix unchecked return status, batch 4

Fix up some hwmon drivers so that they no longer ignore return status
from device_create_file().

Note: f71805f actually checked the status from device_create_file
already. However it did not remove the files on device destruction.
It was also an opportunity to use sysfs_create/remove_group instead
of hand-made loops. This makes the changes much more important but
I think the result is worth it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>