perf trace augmented_syscalls.bpf: Move the renameat aumenter to renameat2, temporarily

perf trace augmented_syscalls.bpf: Move the renameat aumenter to renameat2, temporarily

While trying to shape Howard Chu's generic BPF augmenter transition into
the codebase I got stuck with the renameat2 syscall.

Until I noticed that the attempt at reusing augmenters were making it
use the 'openat' syscall augmenter, that collect just one string syscall
arg, for the 'renameat2' syscall, that takes two strings.

So, for the moment, just to help in this transition period, since
'renameat2' is what is used these days in the 'mv' utility, just make
the BPF collector be associated with the more widely used syscall,
hopefully the transition to Howard's generic BPF augmenter will cure
this, so get this out of the way for now!

So now we still have that odd "reuse", but for something we're not
testing so won't get in the way anymore:

  root@number:~# rm -f 987654 ; touch 123456 ; perf trace -vv -e rename* mv 123456 987654 |& grep renameat
  Reusing "openat" BPF sys_enter augmenter for "renameat"
       0.000 ( 0.079 ms): mv/1158612 renameat2(olddfd: CWD, oldname: "123456", newdfd: CWD, newname: "987654", flags: NOREPLACE) = 0
  root@number:~#

Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Howard Chu <howardchu95@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/CAP-5=fXjGYs=tpBgETK-P9U-CuXssytk9pSnTXpfphrmmOydWA@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>