[#110] tree: Update errors to switch endpoint

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

internal/frostfs/services/tree_client_grpc.go

@@ -18,8 +18,6 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
 )
 
 type GetNodeByPathResponseInfoWrapper struct {
@@ -346,31 +344,9 @@ func (c *ServiceClientGRPC) requestWithRetry(fn func(client treeClient) error) (
 }
 
 func shouldTryAgain(err error) bool {
-	if err == nil {
-		return false
-	}
-
-	code := status.Code(unwrapErr(err))
-	if code == codes.Unavailable || code == codes.Unimplemented {
-		return true
-	}
-
-	errText := err.Error()
-	if strings.Contains(errText, "not found") ||
-		strings.Contains(errText, "shard is in read-only mode") ||
-		strings.Contains(errText, "shard is in degraded mode") {
-		return true
-	}
-
-	return false
-}
-
-func unwrapErr(err error) error {
-	for e := errors.Unwrap(err); e != nil; e = errors.Unwrap(err) {
-		err = e
-	}
-
-	return err
+	return !(err == nil ||
+		errors.Is(err, tree.ErrNodeNotFound) ||
+		errors.Is(err, tree.ErrNodeAccessDenied))
 }
 
 func metaToKV(meta map[string]string) []*grpcService.KeyValue {