usb: gadget: use usb_string_ids_tab instead multiple usb_string_id()

Using usb_string_ids_tab() instead multiple calls of usb_string_id()
seems to be handy. It also allows to add string without many checks.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/gmidi.c b/drivers/usb/gadget/gmidi.c
index 0c70708..68f8c03 100644
--- a/drivers/usb/gadget/gmidi.c
+++ b/drivers/usb/gadget/gmidi.c
@@ -140,25 +140,12 @@
 	struct usb_gadget *gadget = cdev->gadget;
 	int gcnum, status;
 
-	status = usb_string_id(cdev);
+	status = usb_string_ids_tab(cdev, strings_dev);
 	if (status < 0)
 		return status;
-	strings_dev[STRING_MANUFACTURER_IDX].id = status;
-	device_desc.iManufacturer = status;
-
-	status = usb_string_id(cdev);
-	if (status < 0)
-		return status;
-	strings_dev[STRING_PRODUCT_IDX].id = status;
-	device_desc.iProduct = status;
-
-	/* config description */
-	status = usb_string_id(cdev);
-	if (status < 0)
-		return status;
-	strings_dev[STRING_DESCRIPTION_IDX].id = status;
-
-	midi_config.iConfiguration = status;
+	device_desc.iManufacturer = strings_dev[STRING_MANUFACTURER_IDX].id;
+	device_desc.iProduct = strings_dev[STRING_PRODUCT_IDX].id;
+	midi_config.iConfiguration = strings_dev[STRING_DESCRIPTION_IDX].id;
 
 	gcnum = usb_gadget_controller_number(gadget);
 	if (gcnum < 0) {