Memory disclosure/buffer overread on audit plugin

after executing a query, a buffer overread is happening while writing the query on the audit file. this bug will happen with the current version (1.3.0)

the query looks like: SET PASSWORD FOR `monitor`@`localhost` = password('test123');
the output looks like: 20150429 11:54:31,hostname123,root,localhost,109,442,QUERY,,'SET PASSWORD FOR `monitor`@`localhost`=<secret>*****�)1P��)root)�-��XM.localhost