backends/cryptodev: remove dead code

Fix Coverity issue 1390600.

Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Message-Id: <1524894864-7492-1-git-send-email-jianjay.zhou@huawei.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/backends/cryptodev-vhost-user.c b/backends/cryptodev-vhost-user.c
index d52dacc..d539f14 100644
--- a/backends/cryptodev-vhost-user.c
+++ b/backends/cryptodev-vhost-user.c
@@ -157,7 +157,6 @@
 {
     CryptoDevBackendVhostUser *s = opaque;
     CryptoDevBackend *b = CRYPTODEV_BACKEND(s);
-    Error *err = NULL;
     int queues = b->conf.peers.queues;
 
     assert(queues < MAX_CRYPTO_QUEUE_NUM);
@@ -174,10 +173,6 @@
         cryptodev_vhost_user_stop(queues, s);
         break;
     }
-
-    if (err) {
-        error_report_err(err);
-    }
 }
 
 static void cryptodev_vhost_user_init(