add postpone ctx to loopback (#552)

Signed-off-by: Nikita Skrynnik <nikita.skrynnik@xored.com>

pkg/networkservice/loopback/client.go

@@ -27,6 +27,7 @@ import (
 	"github.com/networkservicemesh/api/pkg/api/networkservice"
 	"github.com/networkservicemesh/sdk/pkg/networkservice/core/next"
 	"github.com/networkservicemesh/sdk/pkg/networkservice/utils/metadata"
+	"github.com/networkservicemesh/sdk/pkg/tools/postpone"
 )
 
 type loopbackClient struct {
@@ -55,9 +56,12 @@ func (l *loopbackClient) Request(ctx context.Context, request *networkservice.Ne
 	if err := createLoopback(ctx, l.vppConn, networkService, l.loopbacks, metadata.IsClient(l)); err != nil {
 		return nil, err
 	}
+	postponeCtxFunc := postpone.Context(ctx)
 	conn, err := next.Client(ctx).Request(ctx, request, opts...)
 	if err != nil {
-		del(ctx, l.vppConn, networkService, l.loopbacks, metadata.IsClient(l))
+		closeCtx, cancelClose := postponeCtxFunc()
+		defer cancelClose()
+		del(closeCtx, l.vppConn, networkService, l.loopbacks, metadata.IsClient(l))
 	}
 	return conn, err
 }