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 <johan@kernel.org>

drivers/usb/serial/f81534.c

@@ -634,7 +634,7 @@ static int f81534_calc_num_ports(struct usb_serial *serial,
 	if (status) {
 		dev_err(&serial->interface->dev, "%s: find idx failed: %d\n",
 				__func__, status);
-		return 0;
+		return status;
 	}
 
 	/*
@@ -650,7 +650,7 @@ static int f81534_calc_num_ports(struct usb_serial *serial,
 			dev_err(&serial->interface->dev,
 					"%s: get custom data failed: %d\n",
 					__func__, status);
-			return 0;
+			return status;
 		}
 
 		dev_dbg(&serial->interface->dev,
@@ -666,7 +666,7 @@ static int f81534_calc_num_ports(struct usb_serial *serial,
 			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",