refactor: eslint fix

src/core/system.js

@@ -29,8 +29,7 @@
         "L": 24
     };
 
-    var provider = function () {
-
+    function provider () {
         this.SYSTEM = system;
 
         this.setSize = function (opt) {
@@ -91,10 +90,10 @@
                 }
             });
         };
-    };
+    }
 
     BI.provider("bi.provider.system", provider);
-})();
+}());
 
 BI.prepares.push(function () {
     BI.SIZE_CONSANTS = BI.Providers.getProvider("bi.provider.system").getSize();