Remove a dead variable from ldmd. (It used to be used to pass an extra -help to ldc when no files were specified, but we handle that in ldc itself now)

module bug79;
import std.c.linux.linux;
void main()
{
    timespec ts; 
    ts.tv_nsec -= 1;
    //auto t = ts.tv_nsec - 1;
    //t -= 1;
}