USB: gadget: g_multi: moved strings handling code to composite

This patch removes some of the string registration from the
Multifunction Composite Gadget as composite layer can handle
the iManufacturer and iProduct for us.

This also adds the "needs_serial" so that composite layer will
issue a warning if user space fails to provide the iSerialNumber
module parameter.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/multi.c b/drivers/usb/gadget/multi.c
index 36d67a3..ca51661 100644
--- a/drivers/usb/gadget/multi.c
+++ b/drivers/usb/gadget/multi.c
@@ -121,8 +121,6 @@
 
 
 enum {
-	MULTI_STRING_MANUFACTURER_IDX,
-	MULTI_STRING_PRODUCT_IDX,
 #ifdef CONFIG_USB_G_MULTI_RNDIS
 	MULTI_STRING_RNDIS_CONFIG_IDX,
 #endif
@@ -131,11 +129,7 @@
 #endif
 };
 
-static char manufacturer[50];
-
 static struct usb_string strings_dev[] = {
-	[MULTI_STRING_MANUFACTURER_IDX].s = manufacturer,
-	[MULTI_STRING_PRODUCT_IDX].s      = DRIVER_DESC,
 #ifdef CONFIG_USB_G_MULTI_RNDIS
 	[MULTI_STRING_RNDIS_CONFIG_IDX].s = "Multifunction with RNDIS",
 #endif
@@ -314,20 +308,11 @@
 		device_desc.bcdDevice = cpu_to_le16(0x0300 | 0x0099);
 	}
 
-	/* allocate string descriptor numbers */
-	snprintf(manufacturer, sizeof manufacturer, "%s %s with %s",
-	         init_utsname()->sysname, init_utsname()->release,
-	         gadget->name);
-
+	/* allocate string IDs */
 	status = usb_string_ids_tab(cdev, strings_dev);
 	if (unlikely(status < 0))
 		goto fail2;
 
-	device_desc.iManufacturer =
-		strings_dev[MULTI_STRING_MANUFACTURER_IDX].id;
-	device_desc.iProduct      =
-		strings_dev[MULTI_STRING_PRODUCT_IDX].id;
-
 	/* register configurations */
 	status = rndis_config_register(cdev);
 	if (unlikely(status < 0))
@@ -370,6 +355,8 @@
 	.strings	= dev_strings,
 	.bind		= multi_bind,
 	.unbind		= __exit_p(multi_unbind),
+	.iProduct	= DRIVER_DESC,
+	.needs_serial	= 1,
 };