samples/bpf: Fix typo in README

Fix 'cofiguration' typo in BPF samples README.

Signed-off-by: Kang Minchul <tegongkang@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221030180254.34138-1-tegongkang@gmail.com