minor: reset error on tput.

lib/tput.js

@@ -53,6 +53,7 @@ function Tput(options) {
   this.extended = options.extended;
   this.printf = options.printf;
   this.termcap = options.termcap;
+  this.error = null;
 
   this.terminfoPrefix = options.terminfoPrefix;
   this.terminfoFile = options.terminfoFile;
@@ -64,6 +65,7 @@ function Tput(options) {
 }
 
 Tput.prototype.setup = function() {
+  this.error = null;
   try {
     if (this.termcap) {
       try {