hwmon: (hih6130) Fix documentation of struct hih6130

Sparse reports:

drivers/hwmon/hih6130.c:56: warning:
	No description found for parameter 'client'
drivers/hwmon/hih6130.c:56: warning:
	Excess struct member 'hwmon_dev' description in 'hih6130'
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/hih6130.c

@@ -37,7 +37,7 @@
 
 /**
  * struct hih6130 - HIH-6130 device specific data
- * @hwmon_dev: device registered with hwmon
+ * @client: pointer to I2C client device
  * @lock: mutex to protect measurement values
  * @valid: only false before first measurement is taken
  * @last_update: time of last update (jiffies)