selftests/bpf: Make cgroup_v1v2 use its own port

This patch change cgroup_v1v2 use a different port, avoid conflict with
other tests.

Signed-off-by: Yucong Sun <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/testing/selftests/bpf/prog_tests/cgroup_v1v2.c

···
 {
 	struct network_helper_opts opts = {};
 	int server_fd, client_fd, cgroup_fd;
-	static const int port = 60123;
+	static const int port = 60120;
 
 	/* Step 1: Check base connectivity works without any BPF. */
 	server_fd = start_server(AF_INET, SOCK_STREAM, NULL, port, 0);

tools/testing/selftests/bpf/progs/connect4_dropper.c

···
 {
 	if (ctx->type != SOCK_STREAM)
 		return VERDICT_PROCEED;
-	if (ctx->user_port == bpf_htons(60123))
+	if (ctx->user_port == bpf_htons(60120))
 		return VERDICT_REJECT;
 	return VERDICT_PROCEED;
 }