perf beauty: Add generator for fspick's 'flags' arg values

perf beauty: Add generator for fspick's 'flags' arg values

  $ tools/perf/trace/beauty/fspick.sh
  static const char *fspick_flags[] = {
          [ilog2(0x00000001) + 1] = "CLOEXEC",
          [ilog2(0x00000002) + 1] = "SYMLINK_NOFOLLOW",
          [ilog2(0x00000004) + 1] = "NO_AUTOMOUNT",
          [ilog2(0x00000008) + 1] = "EMPTY_PATH",
  };
  $

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-8i16btocq1ax2u6542ya79t5@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>