x86/traceponit: Fix comment about irq vector tracepoints

Commit:

  4b9a8dca ("x86/idt: Remove the tracing IDT completely")

removed the 'tracing IDT' from arch/x86/kernel/tracepoint.c,
but left related comment. So that the comment become anachronistic.
Just remove the comment.

Link: https://lkml.kernel.org/r/20220526110831.175743-1-sunliming@kylinos.cn



Signed-off-by: sunliming <sunliming@kylinos.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>