perf build: Stop using __weak bpf_map_create() to handle older libbpf versions

By adding a feature test for bpf_map_create() and providing a fallback if
it isn't present in older versions of libbpf.

This also fixes the build with torvalds/master at this point:

  $ git log --oneline -5 torvalds/master
  babf0bb9 (torvalds/master) Merge tag 'xfs-5.19-for-linus' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
  e375780b Merge tag 'fsnotify_for_v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
  8b728edc Merge tag 'fs_for_v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
  3f306ea2 Merge tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping
  fbe86dac Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
  $

Coping with:

  $ git log --oneline -2 d16495a9
  d16495a9 libbpf: remove bpf_create_map*() APIs
  e2371b16 libbpf: start 1.0 developm...