crypto: caam - update IV only when crypto operation succeeds

skcipher encryption might fail and in some cases, like (invalid) input
length smaller then block size, updating the IV would lead to a useless
IV copy in case hardware issued an error.

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>