backends/cryptodev: Do not ignore throttle/backends Errors

Both cryptodev_backend_set_throttle() and CryptoDevBackendClass::init()
can set their Error** argument. Do not ignore them, return early
on failure. Without that, running into another failure trips
error_setv()'s assertion. Use the ERRP_GUARD() macro as suggested
in commit ae7c80a7 ("error: New macro ERRP_GUARD()").

Cc: qemu-stable@nongnu.org
Fixes: e7a775fd ("cryptodev: Account statistics")
Fixes: 2580b452 ("cryptodev: support QoS")
Reviewed-by: zhenwei pi <pizhenwei@bytedance.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231120150418.93443-1-philmd@linaro.org>
(cherry picked from commit 484aecf2d3a75251b63481be2a0c3aef635002af)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

backends/cryptodev.c

@@ -398,6 +398,7 @@ static void cryptodev_backend_set_ops(Object *obj, Visitor *v,
 static void
 cryptodev_backend_complete(UserCreatable *uc, Error **errp)
 {
+    ERRP_GUARD();
     CryptoDevBackend *backend = CRYPTODEV_BACKEND(uc);
     CryptoDevBackendClass *bc = CRYPTODEV_BACKEND_GET_CLASS(uc);
     uint32_t services;
@@ -406,11 +407,20 @@ cryptodev_backend_complete(UserCreatable *uc, Error **errp)
     QTAILQ_INIT(&backend->opinfos);
     value = backend->tc.buckets[THROTTLE_OPS_TOTAL].avg;
     cryptodev_backend_set_throttle(backend, THROTTLE_OPS_TOTAL, value, errp);
+    if (*errp) {
+        return;
+    }
     value = backend->tc.buckets[THROTTLE_BPS_TOTAL].avg;
     cryptodev_backend_set_throttle(backend, THROTTLE_BPS_TOTAL, value, errp);
+    if (*errp) {
+        return;
+    }
 
     if (bc->init) {
         bc->init(backend, errp);
+        if (*errp) {
+            return;
+        }
     }
 
     services = backend->conf.crypto_services;