[#178] wrapReader: Fix goroutine leak

In case of error in FrostFS.CreateObject wrapped reader
can be blocked because of synchronous pipe. We have to read out all payload in such case.

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

api/layer/object.go

@@ -469,6 +469,10 @@ func (n *layer) objectPutAndHash(ctx context.Context, prm PrmObjectCreate, bktIn
 	})
 	id, err := n.frostFS.CreateObject(ctx, prm)
 	if err != nil {
+		if _, errDiscard := io.Copy(io.Discard, prm.Payload); errDiscard != nil {
+			n.reqLogger(ctx).Warn("failed to discard put payload, probably goroutine leaks", zap.Error(errDiscard))
+		}
+
 		return 0, oid.ID{}, nil, err
 	}
 	return size, id, hash.Sum(nil), nil