hwmon: (stts751) Remove an unused field in struct stts751_priv

In "struct stts751_priv", the 'smbus_timeout' field is unused.
Remove it.

Found with cppcheck, unusedStructMember.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/94ccf9caaa6b0101351bf381f09f4428c5e0835c.1714511322.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Author: tititiou36

drivers/hwmon/stts751.c

@@ -91,7 +91,6 @@ struct stts751_priv {
 	int event_max, event_min;
 	int therm;
 	int hyst;
-	bool smbus_timeout;
 	int temp;
 	unsigned long last_update, last_alert_update;
 	u8 config;