tls: Trivial use_strict fix

lib/tls.js

@@ -646,15 +646,16 @@ CryptoStream.prototype.destroySoon = function(err) {
     // was written on this side was read from the other side.
     var self = this;
     var waiting = 1;
-    function finish() {
-      if (--waiting === 0) self.destroy();
-    }
     this._opposite.once('end', finish);
     if (!this._finished) {
       this.once('finish', finish);
       ++waiting;
     }
   }
+
+  function finish() {
+    if (--waiting === 0) self.destroy();
+  }
 };