USB: gadget: composite: Don't increment interface number for alt settings.

Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index cf7a5cf..fa785c6 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -326,8 +326,13 @@
 		dest = next;
 		while ((descriptor = *descriptors++) != NULL) {
 			intf = (struct usb_interface_descriptor *)dest;
-			if (intf->bDescriptorType == USB_DT_INTERFACE)
-				intf->bInterfaceNumber = interfaceCount++;
+			if (intf->bDescriptorType == USB_DT_INTERFACE) {
+				/* don't increment bInterfaceNumber for alternate settings */
+				if (intf->bAlternateSetting == 0)
+					intf->bInterfaceNumber = interfaceCount++;
+				else
+					intf->bInterfaceNumber = interfaceCount - 1;
+			}
 			dest += intf->bLength;
 		}