Addressed review comments

Signed-off-by: Oleg Solodkov <oleg.solodkov@xored.com>

pkg/networkservice/common/refresh/client.go

@@ -22,7 +22,6 @@ package refresh
 
 import (
 	"context"
-	"math"
 	"time"
 
 	"github.com/golang/protobuf/ptypes"
@@ -109,7 +108,7 @@ func (t *refreshClient) Close(ctx context.Context, conn *networkservice.Connecti
 func after(ctx context.Context, conn *networkservice.Connection) (time.Duration, error) {
 	clockTime := clock.FromContext(ctx)
 
-	var minTimeout = time.Duration(math.MaxInt64)
+	var minTimeout *time.Duration
 	var expireTime time.Time
 	for _, segment := range conn.GetPath().GetPathSegments() {
 		expTime, err := ptypes.Timestamp(segment.GetExpires())
@@ -119,15 +118,19 @@ func after(ctx context.Context, conn *networkservice.Connection) (time.Duration,
 
 		timeout := clockTime.Until(expTime)
 
-		if timeout < minTimeout {
-			minTimeout = timeout
+		if minTimeout == nil || timeout < *minTimeout {
+			if minTimeout == nil {
+				minTimeout = new(time.Duration)
+			}
+
+			*minTimeout = timeout
 			expireTime = expTime
 		}
 	}
 
 	log.FromContext(ctx).Infof("expiration after %s at %s", minTimeout.String(), expireTime.UTC())
 
-	if minTimeout <= 0 {
+	if minTimeout == nil || *minTimeout <= 0 {
 		return 1, nil
 	}
 
@@ -140,7 +143,7 @@ func after(ctx context.Context, conn *networkservice.Connection) (time.Duration,
 	if len(path.PathSegments) > 1 {
 		scale = 0.2 + 0.2*float64(path.Index)/float64(len(path.PathSegments))
 	}
-	duration := time.Duration(float64(minTimeout) * scale)
+	duration := time.Duration(float64(*minTimeout) * scale)
 
 	return duration, nil
 }