hwmon: (it87) Fix pwm sysfs attribute removal

Detection if a pwm channel is supported was wrong on removal,
causing the code to try removing non-existing sysfs attributes.
That didn't matter much because sysfs attribute removal of non-existing
files fails silently, and because the wrong evaluation always returned
false, but should nevertheless be fixed.
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/it87.c

@@ -2079,7 +2079,7 @@ static void it87_remove_files(struct device *dev)
 					  it87_attributes_fan_div[i]);
 	}
 	for (i = 0; i < 3; i++) {
-		if (sio_data->skip_pwm & (1 << 0))
+		if (sio_data->skip_pwm & (1 << i))
 			continue;
 		sysfs_remove_group(&dev->kobj, &it87_group_pwm[i]);
 		if (has_old_autopwm(data))