Typo.
Cleanup of useless unused argument void casts in C++ files.

Perhaps we should've done this instead:

    //-------------------------------------------------------------------------
    //  Suppress nuisance compiler warnings. Yes, each compiler can already
    //  do this, each differently! VC9 has its UNREFERENCED_PARAMETER(),
    //  which is almost the same as the SUPPRESS_UNUSED_WARNING() below.
    //
    //  We append _UNUSED to the variable name, because the dumb gcc compiler
    //  doesn't bother to tell you if you erroneously _use_ something flagged
    //  with __attribute__((unused)). So we are forced to *mangle* the name.
    //-------------------------------------------------------------------------
    #if defined(__cplusplus)
    #define UNUSED(x)       // = nothing
    #elif defined(__GNUC__)
    #define UNUSED(x)       x##_UNUSED __attribute__((unused))
    #else
    #define UNUSED(x)       x##_UNUSED
    #endif
    ...
    int foo(int UNUSED(bar)) { ... }