perf augmented_syscalls: Convert to bpf_map()

To make the code more compact, end result is the same:

  # perf trace -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_syscalls.c sleep 1
     0.000 ( 0.008 ms): sleep/9663 openat(dfd: CWD, filename: "/etc/ld.so.cache", flags: RDONLY|CLOEXEC) = 3
     0.022 ( 0.005 ms): sleep/9663 openat(dfd: CWD, filename: "/lib64/libc.so.6", flags: RDONLY|CLOEXEC) = 3
     0.226 ( 0.006 ms): sleep/9663 openat(dfd: CWD, filename: "/usr/lib/locale/locale-archive", flags: RDONLY|CLOEXEC) = 3
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-23z08bgizqnbc3qdsyl7jyyg@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>