hwmon: (ads7828) Check return value of devm_regmap_init_i2c

devm_regmap_init_i2c() can fail, thus add return value checking.

Signed-off-by: Axel Lin <[e-mail]>
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/ads7828.c

···
 						    &ads2830_regmap_config);
 	}
 
+	if (IS_ERR(data->regmap))
+		return PTR_ERR(data->regmap);
+
 	data->cmd_byte = ext_vref ? ADS7828_CMD_PD1 : ADS7828_CMD_PD3;
 	if (!diff_input)
 		data->cmd_byte |= ADS7828_CMD_SD_SE;