usb: dwc3: gadget: avoid while(1) in run_stop()

instead of looping forever and forcing a return if
timeout reaches zero, we can just use timeout and
loop's break condition directly.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/gadget.c

@@ -1581,10 +1581,10 @@ static int dwc3_gadget_run_stop(struct dwc3 *dwc, int is_on, int suspend)
 			if (reg & DWC3_DSTS_DEVCTRLHLT)
 				break;
 		}
-		timeout--;
+	} while (--timeout);
+
 	if (!timeout)
 		return -ETIMEDOUT;
-	} while (1);
 
 	dwc3_trace(trace_dwc3_gadget, "gadget %s data soft-%s",
 			dwc->gadget_driver