hwmon: (max6697) fix regmap leak on probe failure

The i2c regmap allocated during probe is never freed.

Switch to using the device managed allocator so that the regmap is
released on probe failures (e.g. probe deferral) and on driver unbind.

Fixes: 3a2a8cc3fe24 ("hwmon: (max6697) Convert to use regmap")
Cc: [e-mail] # 6.12
Cc: Guenter Roeck <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/max6697.c

···
 	struct regmap *regmap;
 	int err;
 
-	regmap = regmap_init_i2c(client, &max6697_regmap_config);
+	regmap = devm_regmap_init_i2c(client, &max6697_regmap_config);
 	if (IS_ERR(regmap))
 		return PTR_ERR(regmap);