usb: gadget: f_ecm: Staticize ecm_alloc

'ecm_alloc' is local to this file. Make it static.
Signed-off-by: NSachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: NFelipe Balbi <balbi@ti.com>

drivers/usb/gadget/f_ecm.c

@@ -995,7 +995,7 @@ static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 	usb_ep_free_request(ecm->notify, ecm->notify_req);
 }
 
-struct usb_function *ecm_alloc(struct usb_function_instance *fi)
+static struct usb_function *ecm_alloc(struct usb_function_instance *fi)
 {
 	struct f_ecm	*ecm;
 	struct f_ecm_opts *opts;