Don't collect results in exit event callback

lib/common/asar.js

@@ -24,14 +24,12 @@
 
   // Clean cache on quit.
   process.on('exit', function() {
-    var archive, p, results;
-    results = [];
+    var archive, p;
     for (p in cachedArchives) {
       if (!hasProp.call(cachedArchives, p)) continue;
       archive = cachedArchives[p];
-      results.push(archive.destroy());
+      archive.destroy();
     }
-    return results;
   });
 
   // Separate asar package's path from full path.