Automated cleanup

--
MOS_MIGRATED_REVID=135816105
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java b/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
index b3a763f..b050b2e 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/BuiltinFunction.java
@@ -197,7 +197,7 @@
   private static String stacktraceToString(StackTraceElement[] elts) {
     StringBuilder b = new StringBuilder();
     for (StackTraceElement e : elts) {
-      b.append(e.toString());
+      b.append(e);
       b.append("\n");
     }
     return b.toString();