crypto: sun8i-ss - fix infinite loop in sun8i_ss_setup_ivs()

There is no i decrement in while (i >= 0) loop.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Fixes: 359e893e ("crypto: sun8i-ss - rework handling of IV")
Acked-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>