Macro scx_ops_load

macro_rules! scx_ops_load {
    ($skel: expr, $ops: ident, $uei: ident) => { ... };
}

struct sched_ext_ops can change over time. If compat.bpf.h::SCX_OPS_DEFINE() is used to define ops, and scx_ops_open!(), scx_ops_load!(), and scx_ops_attach!() are used to open, load and attach it, backward compatibility is automatically maintained where reasonable.