bpf: selftest: Use static globals in tcp_hdr_options and btf_skc_cls_ingress

Some globals in the tcp_hdr_options test and btf_skc_cls_ingress test
are not using static scope. This patch fixes it.

Targeting bpf-next branch as an improvement since it currently does not
break the build.

Fixes: ad2f8eb0095e ("bpf: selftests: Tcp header options")
Fixes: 9a856cae2217 ("bpf: selftest: Add test_btf_skc_cls_ingress")
Signed-off-by: Martin KaFai Lau <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Acked-by: John Fastabend <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

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

···
 #include "test_btf_skc_cls_ingress.skel.h"
 
 static struct test_btf_skc_cls_ingress *skel;
-struct sockaddr_in6 srv_sa6;
+static struct sockaddr_in6 srv_sa6;
 static __u32 duration;
 
 #define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress"

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

···
 #define LO_ADDR6 "::1"
 #define CG_NAME "/tcpbpf-hdr-opt-test"
 
-struct bpf_test_option exp_passive_estab_in;
-struct bpf_test_option exp_active_estab_in;
-struct bpf_test_option exp_passive_fin_in;
-struct bpf_test_option exp_active_fin_in;
-struct hdr_stg exp_passive_hdr_stg;
-struct hdr_stg exp_active_hdr_stg = { .active = true, };
+static struct bpf_test_option exp_passive_estab_in;
+static struct bpf_test_option exp_active_estab_in;
+static struct bpf_test_option exp_passive_fin_in;
+static struct bpf_test_option exp_active_fin_in;
+static struct hdr_stg exp_passive_hdr_stg;
+static struct hdr_stg exp_active_hdr_stg = { .active = true, };
 
 static struct test_misc_tcp_hdr_options *misc_skel;
 static struct test_tcp_hdr_options *skel;