veyron/services/mgmt/build: minor cleanup

Change-Id: I917fd2f32b02d2cabe6693af64c61673782a4651
diff --git a/services/mgmt/build/impl/impl_test.go b/services/mgmt/build/impl/impl_test.go
index fd45724..6084b70 100644
--- a/services/mgmt/build/impl/impl_test.go
+++ b/services/mgmt/build/impl/impl_test.go
@@ -69,15 +69,12 @@
 	}
 	bins := make([]build.File, 0)
 	for stream.Advance() {
-		bin := stream.Value()
-		bins = append(bins, bin)
+		bins = append(bins, stream.Value())
 	}
-
 	if err := stream.Err(); err != nil {
-		t.Logf("Recv() failed: %v", err)
+		t.Logf("Advance() failed: %v", err)
 		return nil, nil, err
 	}
-
 	output, err := stream.Finish()
 	if err != nil {
 		t.Logf("Finish() failed: %v", err)