USB: yurex: remove needless check before usb_free_coherent()

usb_free_coherent() is safe with NULL addr and this check is
not required.
Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20200810020802.9082-1-vulab@iscas.ac.cnSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/yurex.c

@@ -96,15 +96,13 @@ static void yurex_delete(struct kref *kref)
 	if (dev->cntl_urb) {
 		usb_kill_urb(dev->cntl_urb);
 		kfree(dev->cntl_req);
-		if (dev->cntl_buffer)
-			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
+		usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 				dev->cntl_buffer, dev->cntl_urb->transfer_dma);
 		usb_free_urb(dev->cntl_urb);
 	}
 	if (dev->urb) {
 		usb_kill_urb(dev->urb);
-		if (dev->int_buffer)
-			usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
+		usb_free_coherent(dev->udev, YUREX_BUF_SIZE,
 				dev->int_buffer, dev->urb->transfer_dma);
 		usb_free_urb(dev->urb);
 	}