mfd: da9063: Propagate errno when I2C mode fails

Don't hardocde EIO but use the obtained value.

Signed-off-by: Wolfram Sang <[e-mail]>
Reviewed-by: Mark Jonas <[e-mail]>
Signed-off-by: Lee Jones <[e-mail]>

drivers/mfd/da9063-i2c.c

···
 					DA9063_TWOWIRE_TO);
 		if (ret < 0) {
 			dev_err(da9063->dev, "Failed to set Two-Wire Bus Mode.\n");
-			return -EIO;
+			return ret;
 		}
 	}