selftests: bpf: Reset global state between reuseport test runs

selftests: bpf: Reset global state between reuseport test runs

Currently, there is a lot of false positives if a single reuseport test
fails. This is because expected_results and the result map are not cleared.

Zero both after individual test runs, which fixes the mentioned false
positives.

Fixes: 91134d849a0e ("bpf: Test BPF_PROG_TYPE_SK_REUSEPORT")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200124112754.19664-5-lmb@cloudflare.com