crypto: iaa - Fix async_disable descriptor leak

The disable_async paths of iaa_compress/decompress() don't free idxd
descriptors in the async_disable case. Currently this only happens in
the testcases where req->dst is set to null. Add a test to free them
in those paths.
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/intel/iaa/iaa_crypto_main.c

@@ -1222,7 +1222,7 @@ static int iaa_compress(struct crypto_tfm *tfm,	struct acomp_req *req,
 
 	*compression_crc = idxd_desc->iax_completion->crc;
 
-	if (!ctx->async_mode)
+	if (!ctx->async_mode || disable_async)
 		idxd_free_desc(wq, idxd_desc);
 out:
 	return ret;
@@ -1468,7 +1468,7 @@ static int iaa_decompress(struct crypto_tfm *tfm, struct acomp_req *req,
 
 	*dlen = req->dlen;
 
-	if (!ctx->async_mode)
+	if (!ctx->async_mode || disable_async)
 		idxd_free_desc(wq, idxd_desc);
 
 	/* Update stats */