bpflist doesn't show attached probes

[Jerome Marchand]

bpflist -vv shows no attached kprobes or uprobes

$bpflist -vv
open kprobes:

open uprobes:

PID    COMM             TYPE  COUNT
2718   biolatency       map   2
2718   biolatency       prog  2
``

I suspect this is because bpflist looks for the probes in debugfs (/sys/kernel/debug/tracing/{k,u}probe_events) and attach_kprobe uses perf_event_open() syscall when available, which is probably always nowadays.