The copy_to_user() function returns the number of bytes that it wasn't
able to copy. We want to return -EFAULT to the user.
Fixes: fee6efce56 ("ionic: add hw timestamp support files")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>