usb: gadget: uvc: uvc_alloc() can be static

The function isn't called from outside of its compilation unit, make it
static.
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/gadget/function/f_uvc.c

@@ -773,7 +773,7 @@ static void uvc_unbind(struct usb_configuration *c, struct usb_function *f)
 	usb_free_all_descriptors(f);
 }
 
-struct usb_function *uvc_alloc(struct usb_function_instance *fi)
+static struct usb_function *uvc_alloc(struct usb_function_instance *fi)
 {
 	struct uvc_device *uvc;
 	struct f_uvc_opts *opts;