[#1086] engine: Change mode in case of errors async

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

pkg/local_object_storage/engine/error_test.go

@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"testing"
+	"time"
 
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/core/object"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/local_object_storage/blobstor"
@@ -229,6 +230,8 @@ func checkShardState(t *testing.T, e *StorageEngine, id *shard.ID, errCount uint
 	sh := e.shards[id.String()]
 	e.mtx.RUnlock()
 
-	require.Equal(t, errCount, sh.errorCount.Load())
-	require.Equal(t, mode, sh.GetMode())
+	require.Eventually(t, func() bool {
+		return errCount == sh.errorCount.Load() &&
+			mode == sh.GetMode()
+	}, 10*time.Second, 10*time.Millisecond, "shard mode doesn't changed to expected state in 10 seconds")
 }