USB: serial: f81534: abort probe on early errors

We can now abort probe early after an error in calc_num_ports by
returning an errno instead of attempting to continue probing but not
register any ports.

Signed-off-by: Johan Hovold <[e-mail]>

drivers/usb/serial/f81534.c

···
 	if (status) {
 		dev_err(&serial->interface->dev, "%s: find idx failed: %d\n",
 				__func__, status);
-		return 0;
+		return status;
 	}
 
 	/*
···
 			dev_err(&serial->interface->dev,
 					"%s: get custom data failed: %d\n",
 					__func__, status);
-			return 0;
+			return status;
 		}
 
 		dev_dbg(&serial->interface->dev,
···
 			dev_err(&serial->interface->dev,
 					"%s: read failed: %d\n", __func__,
 					status);
-			return 0;
+			return status;
 		}
 
 		dev_dbg(&serial->interface->dev, "%s: read default config\n",