[NTOS:FSRTL] Check for the correct return status when inserting a new Filter Context entry According to our declaration/definition, IoChangeFileObjectFilerContext returns NTSTATUS, not BOOLEAN. Zero return (which was actually checked before) for BOOLEAN means failure, but for NTSTATUS it's success. So it should (and now actually does) free and fail appropriately only in failure case, but not in success, when it shouldn't. This fixes most of problems with fltmgr.sys driver from Windows XP/Server 2003 and a lot of 3rd party filter drivers which use it from many apps (Avast Free Antivirus all versions, Avira AntiVir Personal 8.2, Dr. Web Security Space 8.0, Kaspersky Antivirus 2012 etc. etc.). CORE-14157, CORE-14635, CORE-19318 master