We were copying the last ciphertext block into the IV field
for CBC before removing the DMA mapping of the output buffer
with the result of the buffer sometime being out-of-sync cache
wise and were getting intermittent cases of bad output IV.

Fix it by moving the DMA buffer unmapping before the copy.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Fixes: 00904aa0 ("crypto: ccree - fix iv handling")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>