[MERGE #3240 @xiaoyinl] Fix memory leak in WScriptJsrt::LoadTextFileCallback
[MERGE #3240 @xiaoyinl] Fix memory leak in WScriptJsrt::LoadTextFileCallback

Merge pull request #3240 from xiaoyinl:filecontent_leak

`fileContent` should be freed when `ChakraRTInterface::JsCreateString` fails.

mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,mrkmarron/ChakraCore,Microsoft/ChakraCore,Microsoft/ChakraCore