VOL-2139 update tests to use voltha-lib-go instead of voltha-go

Change-Id: I7581bf051e8aede6c46abb894b14c5871b713378
diff --git a/tests/core/performance_metrics_test.go b/tests/core/performance_metrics_test.go
index 9e074f5..94b5826 100644
--- a/tests/core/performance_metrics_test.go
+++ b/tests/core/performance_metrics_test.go
@@ -21,8 +21,8 @@
 	"context"
 	"fmt"
 	"github.com/google/uuid"
-	"github.com/opencord/voltha-go/common/log"
 	tu "github.com/opencord/voltha-go/tests/utils"
+	"github.com/opencord/voltha-lib-go/pkg/log"
 	"github.com/opencord/voltha-protos/go/common"
 	"github.com/opencord/voltha-protos/go/voltha"
 	"github.com/stretchr/testify/assert"