crypto: atmel-aes - fix atmel_aes_handle_queue()

This patch fixes the value returned by atmel_aes_handle_queue(), which
could have been wrong previously when the crypto request was started
synchronously but became asynchronous during the ctx->start() call.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/atmel-aes.c

@@ -879,6 +879,7 @@ static int atmel_aes_handle_queue(struct atmel_aes_dev *dd,
 	struct crypto_async_request *areq, *backlog;
 	struct atmel_aes_base_ctx *ctx;
 	unsigned long flags;
+	bool start_async;
 	int err, ret = 0;
 
 	spin_lock_irqsave(&dd->lock, flags);
@@ -904,10 +905,12 @@ static int atmel_aes_handle_queue(struct atmel_aes_dev *dd,
 
 	dd->areq = areq;
 	dd->ctx = ctx;
-	dd->is_async = (areq != new_areq);
+	start_async = (areq != new_areq);
+	dd->is_async = start_async;
 
+	/* WARNING: ctx->start() MAY change dd->is_async. */
 	err = ctx->start(dd);
-	return (dd->is_async) ? ret : err;
+	return (start_async) ? ret : err;
 }