MAGETWO-51544: [Github] Cannot upgrade to Magento 2.0.4 #4013

- Minor update to address code review comment.
- Moved variable assignment towards end of the block

setup/src/Magento/Setup/Model/Cron/ReadinessCheck.php

@@ -131,8 +131,8 @@ public function runReadinessCheck()
             $resultJsonRawData[self::KEY_FILE_PATHS][self::KEY_LIST] = $filePaths;
         } catch (\Exception $e) {
             $errorMsg = $e->getMessage();
-            $returnValue = false;
             $resultJsonRawData[self::KEY_FILE_PATHS][self::KEY_LIST] = [];
+            $returnValue = false;
         }
         $resultJsonRawData[self::KEY_FILE_PATHS][self::KEY_ERROR] = $errorMsg;