When the ring is full, size == array_size. It is not an error condition,
so simply return 0 instead of an error.
Signed-off-by: NStefano Stabellini <stefanos@xilinx.com>
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>