hwmon: (ad7414) Return proper error code for ad7414_probe()

Return proper error if i2c_check_functionality reports
the adapter does not support the capability we need.

Also remove unneeded initialization for err variable.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

drivers/hwmon/ad7414.c

@@ -178,11 +178,13 @@ static int ad7414_probe(struct i2c_client *client,
 {
 	struct ad7414_data *data;
 	int conf;
-	int err = 0;
+	int err;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
-				     I2C_FUNC_SMBUS_READ_WORD_DATA))
+				     I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+		err = -EOPNOTSUPP;
 		goto exit;
+	}
 
 	data = kzalloc(sizeof(struct ad7414_data), GFP_KERNEL);
 	if (!data) {