hwmon: (emc2103) Return error from i2c_smbus_read_byte_data

There is no reason to replace one error with another.

smatch message:
drivers/hwmon/emc2103.c:352 set_fan_div() info: why not propagate 'status'
from i2c_smbus_read_byte_data() instead of (-5)?

Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>