bpf: selftests: test_tunnel: Setup fresh topology for each subtest

This helps with determinism b/c individual setup/teardown prevents
leaking state between different subtests.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/0fb59fa16fb58cca7def5239df606005a3e8dd0e.1702593901.git.dxu@dxuuu.xyzSigned-off-by: Alexei Starovoitov <ast@kernel.org>

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

@@ -535,23 +535,20 @@ static void test_ipip_tunnel(enum ipip_encap encap)
 #define RUN_TEST(name, ...)						\
 	({								\
 		if (test__start_subtest(#name)) {			\
+			config_device();				\
 			test_ ## name(__VA_ARGS__);			\
+			cleanup();					\
 		}							\
 	})
 
 static void *test_tunnel_run_tests(void *arg)
 {
-	cleanup();
-	config_device();
-
 	RUN_TEST(vxlan_tunnel);
 	RUN_TEST(ip6vxlan_tunnel);
 	RUN_TEST(ipip_tunnel, NONE);
 	RUN_TEST(ipip_tunnel, FOU);
 	RUN_TEST(ipip_tunnel, GUE);
 
-	cleanup();
-
 	return NULL;
 }