Fix AstPrinter::VisitCallRuntime to not print garbage.

R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/1329133002

Cr-Commit-Position: refs/heads/master@{#30633}

src/prettyprinter.cc

@@ -1532,8 +1532,8 @@ void AstPrinter::VisitCallNew(CallNew* node) {
 
 void AstPrinter::VisitCallRuntime(CallRuntime* node) {
   EmbeddedVector<char, 128> buf;
+  SNPrintF(buf, "CALL RUNTIME %s", node->debug_name());
   IndentedScope indent(this, buf.start());
-  Print("NAME %s\n", node->debug_name());
   PrintArguments(node->arguments());
 }