[#1254] policer: Fix svacer warning

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

pkg/services/policer/ec.go

@@ -25,7 +25,7 @@ type ecChunkProcessResult struct {
 	removeLocal    bool
 }
 
-var errInvalidECPlacement = errors.New("invalid EC placement: EC placement must have one placement vector")
+var errInvalidECPlacement = errors.New("invalid EC placement: EC placement must have one placement vector with at least one node")
 
 func (p *Policer) processECContainerObject(ctx context.Context, objInfo objectcore.Info, policy netmap.PlacementPolicy) error {
 	if objInfo.ECInfo == nil {
@@ -42,7 +42,7 @@ func (p *Policer) processECContainerRepObject(ctx context.Context, objInfo objec
 	if err != nil {
 		return fmt.Errorf("%s: %w", logs.PolicerCouldNotBuildPlacementVectorForObject, err)
 	}
-	if len(nn) != 1 {
+	if len(nn) != 1 || len(nn[0]) == 0 {
 		return errInvalidECPlacement
 	}
 
@@ -72,7 +72,7 @@ func (p *Policer) processECContainerECObject(ctx context.Context, objInfo object
 	if err != nil {
 		return fmt.Errorf("%s: %w", logs.PolicerCouldNotBuildPlacementVectorForObject, err)
 	}
-	if len(nn) != 1 {
+	if len(nn) != 1 || len(nn[0]) == 0 {
 		return errInvalidECPlacement
 	}