usb: renesas_usbhs: gadget: fix unused-but-set-variable warning

The commit b8b9c974 ("usb: renesas_usbhs: gadget: disable all eps
when the driver stops") causes the unused-but-set-variable warning.
But, if the usbhsg_ep_disable() will return non-zero value, udc/core.c
doesn't clear the ep->enabled flag. So, this driver should not return
non-zero value, if the pipe is zero because this means the pipe is
already disabled. Otherwise, the ep->enabled flag is never cleared
when the usbhsg_ep_disable() is called by the renesas_usbhs driver first.

Fixes: b8b9c974 ("usb: renesas_usbhs: gadget: disable all eps when the driver stops")
Fixes: 11432050 ("usb: renesas_usbhs: gadget: fix NULL pointer dereference in ep_disable()")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/renesas_usbhs/mod_gadget.c

@@ -639,14 +639,11 @@ static int usbhsg_ep_disable(struct usb_ep *ep)
 	struct usbhsg_uep *uep = usbhsg_ep_to_uep(ep);
 	struct usbhs_pipe *pipe;
 	unsigned long flags;
-	int ret = 0;
 
 	spin_lock_irqsave(&uep->lock, flags);
 	pipe = usbhsg_uep_to_pipe(uep);
-	if (!pipe) {
-		ret = -EINVAL;
+	if (!pipe)
 		goto out;
-	}
 
 	usbhsg_pipe_disable(uep);
 	usbhs_pipe_free(pipe);