ieee802154: Use kmemdup instead of duplicating it in ca8210_test_int_driver_write

Replace calls to kmalloc followed by a memcpy with a direct call to
kmemdup.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>

drivers/net/ieee802154/ca8210.c

@@ -634,10 +634,9 @@ static int ca8210_test_int_driver_write(
 	for (i = 0; i < len; i++)
 		dev_dbg(&priv->spi->dev, "%#03x\n", buf[i]);
 
-	fifo_buffer = kmalloc(len, GFP_KERNEL);
+	fifo_buffer = kmemdup(buf, len, GFP_KERNEL);
 	if (!fifo_buffer)
 		return -ENOMEM;
-	memcpy(fifo_buffer, buf, len);
 	kfifo_in(&test->up_fifo, &fifo_buffer, 4);
 	wake_up_interruptible(&priv->test.readq);