Apply php-cs-fixer rule for array_key_exists()

Author: nicolas-grekas

Form/DoctrineOrmTypeGuesser.php

@@ -157,7 +157,7 @@ protected function getMetadata($class)
         // normalize class name
         $class = ClassUtils::getRealClass(ltrim($class, '\\'));
 
-        if (array_key_exists($class, $this->cache)) {
+        if (\array_key_exists($class, $this->cache)) {
             return $this->cache[$class];
         }