crypto: af_alg - cast ki_complete ternary op to int

when libkcapi test is executed  using HW accelerator, cipher operation
return -74.Since af_alg_async_cb->ki_complete treat err as unsigned int,
libkcapi receive 429467222 even though it expect -ve value.

Hence its required to cast resultlen to int so that proper
error is returned to libkcapi.

AEAD one shot non-aligned test 2(libkcapi test)
./../bin/kcapi   -x 10   -c "gcm(aes)" -i 7815d4b06ae50c9c56e87bd7
-k ea38ac0c9b9998c80e28fb496a2b88d9 -a
"853f98a750098bec1aa7497e979e78098155c877879556bb51ddeb6374cbaefc"
-t "c4ce58985b7203094be1d134c1b8ab0b" -q
"b03692f86d1b8b39baf2abb255197c98"

Fixes: d887c52d

 ("crypto: algif_aead - overhaul memory management")
Cc: <stable@vger.kernel.org>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Atul Gupta <atul.gupta@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>