Fix references

Author: Robin Cawser

EventListener/IdGeneratorListener.php

@@ -63,7 +63,7 @@ private function generateId($property, Vivait\StringGenerator $annotation)
             ->setAlphabet($annotation->alphabet)
             ->setLength($annotation->length);
 
-        $id = $$this->generator->generate();
+        $id = $generator->generate();
 
         if ($annotation->prefix) {
             $id = sprintf("%s%s%s", $annotation->prefix, $annotation->separator, $id);

Generator/StringGenerator.php

@@ -26,7 +26,7 @@ public function generate()
     {
         $str = [];
         $alphaLength = strlen($this->alphabet) - 1;
-        for ($i = 0; $i < $$this->length; $i++) {
+        for ($i = 0; $i < $this->length; $i++) {
             $n = rand(0, $alphaLength);
             $str[] = $this->alphabet[$n];
         }