iio: accel: adxl380: fix handling of unavailable "INT1" interrupt

fwnode_irq_get_byname() returns a negative value on failure; if a negative
value is returned, use it as `err` argument for dev_err_probe().
While at it, add a missing trailing newline to the dev_err_probe() error
message.

Fixes: df36de13677a ("iio: accel: add ADXL380 driver")
Signed-off-by: Francesco Lavra <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Nuno Sá <[e-mail]>
Cc: [e-mail]
Signed-off-by: Jonathan Cameron <[e-mail]>

drivers/iio/accel/adxl380.c

···
 		st->int_map[1] = ADXL380_INT0_MAP1_REG;
 	} else {
 		st->irq = fwnode_irq_get_byname(dev_fwnode(st->dev), "INT1");
-		if (st->irq > 0)
-			return dev_err_probe(st->dev, -ENODEV,
-					     "no interrupt name specified");
+		if (st->irq < 0)
+			return dev_err_probe(st->dev, st->irq,
+					     "no interrupt name specified\n");
 		st->int_map[0] = ADXL380_INT1_MAP0_REG;
 		st->int_map[1] = ADXL380_INT1_MAP1_REG;
 	}