Correct and improve doc block of RouteCollection::match()

Plus remove unused variable.

src/Routing/RouteCollection.php

@@ -272,22 +272,23 @@ protected function _getNames($url)
     }
 
     /**
-     * Reverse route or match a $url array with the defined routes.
-     * Returns either the string URL generate by the route, or false on failure.
+     * Reverse route or match a $url array with the connected routes.
      *
-     * @param array $url The url to match.
+     * Returns either the URL string generated by the route,
+     * or throws an exception on failure.
+     *
+     * @param array $url The URL to match.
      * @param array $context The request context to use. Contains _base, _port,
      *    _host, _scheme and params keys.
-     * @return string|false Either a string on match, or false on failure.
-     * @throws \Cake\Routing\Exception\MissingRouteException when a route cannot be matched.
+     * @return string The URL string on match.
+     * @throws \Cake\Routing\Exception\MissingRouteException When no route could be matched.
      */
     public function match($url, $context)
     {
         // Named routes support optimization.
         if (isset($url['_name'])) {
             $name = $url['_name'];
             unset($url['_name']);
-            $out = false;
             if (isset($this->_named[$name])) {
                 $route = $this->_named[$name];
                 $out = $route->match($url + $route->defaults, $context);