hwmon: (lm90) simplify getting the adapter of a client

We have a dedicated pointer for that, so use it. Much easier to read and
less computation involved.

Reported-by: Peter Rosin <[e-mail]>
Signed-off-by: Wolfram Sang <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/lm90.c

···
 		      const struct i2c_device_id *id)
 {
 	struct device *dev = &client->dev;
-	struct i2c_adapter *adapter = to_i2c_adapter(dev->parent);
+	struct i2c_adapter *adapter = client->adapter;
 	struct hwmon_channel_info *info;
 	struct regulator *regulator;
 	struct device *hwmon_dev;