TBR Fix bug in optional convertibility check, also minor cleanup.

MultiPart: 2/4
Change-Id: If344c12a477379212b6db1880ac600f283e0f30f
diff --git a/test/fortune/fortune.vdl.go b/test/fortune/fortune.vdl.go
index 1cdf380..87c5051 100644
--- a/test/fortune/fortune.vdl.go
+++ b/test/fortune/fortune.vdl.go
@@ -281,7 +281,7 @@
 		return err
 	}
 	if (dec.StackDepth() == 1 || dec.IsAny()) && !vdl.Compatible(vdl.TypeOf(*x), dec.Type()) {
-		return fmt.Errorf("incompatible array %T, from %v", *x, dec.Type())
+		return fmt.Errorf("incompatible list %T, from %v", *x, dec.Type())
 	}
 	switch len := dec.LenHint(); {
 	case len == 0: