hwmon: (lm92) Fix whitespace issues

Smatch complains:

drivers/hwmon/lm92.c:209 set_temp_hyst() warn: inconsistent indenting

While at it, fix various other whitespace issues reported by checkpatch
(double empty lines, missing empty lines, whitespace at empty line).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>