perf probe-event: Un-hardcode sizeof(buf)

perf probe-event: Un-hardcode sizeof(buf)

In several places we had

  char buf[64];
  ...
  snprintf(buf, 64, ...);

This patch changes it to

  char buf[64];
  ...
  snprintf(buf, sizeof(buf), ...);

so the "64" is only stated once.

Signed-off-by: Dima Kogan <dima@secretsauce.net>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20240416045533.162692-2-dima@secretsauce.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>