Start delete state procedure.

PRL_RESULT PrlDisk_DeleteState(
    const PRL_HANDLE Handle, 
    PRL_CONST_STR pDirectoryName, 
    PRL_CONST_GUID_PTR pUid, 
    const PRL_BOOL bMerge, 
    const PRL_STATES_CALLBACK pCallback, 
    PRL_VOID_PTR pParameter
);