Report Extended Error Codes

When a general error (KVERR_General) is generated during out-of-process filtering, extended error codes can also be generated and reported in the error log. The extended error codes provide more information about the error, and are defined in KVErrorCodeEx in kvtypes.h.

To report extended errors, call the function fpGetKvErrorCodeEx(). Extended error codes are generated in the C sample program, Filter.