remove step: last function refactor

lib/cartodb/backends/filter-stats.js

@@ -38,14 +38,14 @@ FilterStatsBackends.prototype.getFilterStats = function (username, unfiltered_qu
             var query = analysisFilter.sql(unfiltered_query);
             getEstimatedRows(self.pgQueryRunner, username, query, function (err, rows) {
                 if (err){
-                    callback(err);
-                    return;
+                    return callback(err);
                 }
-                stats.filtered_rows = rows;
-                callback(null, stats);
-            });
-        }
 
-        callback(null, stats);
+                stats.filtered_rows = rows;
+                return callback(null, stats);
+            });
+        } else {
+            return callback(null, stats);
+        }
     })
 };