fix: race

pkg/file/redundancy/getter/getter.go

@@ -357,6 +357,8 @@ func (g *decoder) fly(i int) (success bool) {
 
 // save iterate over reconstructed shards and puts the corresponding chunks to local storage
 func (g *decoder) save(ctx context.Context, missing []int) error {
+	g.mu.Lock()
+	defer g.mu.Unlock()
 	for _, i := range missing {
 		if err := g.putter.Put(ctx, swarm.NewChunk(g.addrs[i], g.rsbuf[i])); err != nil {
 			return err