crypto: omap-sham - backlog handling fix

Previous commit "removed redundant locking" introduced
a bug in handling backlog.
In certain cases, when async request complete callback will
call complete() on -EINPROGRESS code, it will cause uncompleted requests.
It does not happen in implementation similar to crypto test manager,
but it will happen in implementation similar to dm-crypt.
Backlog needs to be checked before dequeuing next request.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-sham.c

@@ -664,7 +664,7 @@ static void omap_sham_finish_req(struct ahash_request *req, int err)
 static int omap_sham_handle_queue(struct omap_sham_dev *dd,
 				  struct ahash_request *req)
 {
-	struct crypto_async_request *async_req, *backlog = 0;
+	struct crypto_async_request *async_req, *backlog;
 	struct omap_sham_reqctx *ctx;
 	struct ahash_request *prev_req;
 	unsigned long flags;
@@ -677,11 +677,10 @@ static int omap_sham_handle_queue(struct omap_sham_dev *dd,
 		spin_unlock_irqrestore(&dd->lock, flags);
 		return ret;
 	}
+	backlog = crypto_get_backlog(&dd->queue);
 	async_req = crypto_dequeue_request(&dd->queue);
-	if (async_req) {
+	if (async_req)
 		dd->flags |= FLAGS_BUSY;
-		backlog = crypto_get_backlog(&dd->queue);
-	}
 	spin_unlock_irqrestore(&dd->lock, flags);
 
 	if (!async_req)