selftests/landlock: Redefine TEST_F() as TEST_F_FORK()

This has the effect of creating a new test process for either TEST_F()
or TEST_F_FORK(), which doesn't change tests but will ease potential
backports.  See next commit for the TEST_F_FORK() merge into TEST_F().

Cc: Günther Noack <gnoack@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Will Drewry <wad@chromium.org>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/landlock/common.h

@@ -37,7 +37,7 @@
 		struct __test_metadata *_metadata, \
 		FIXTURE_DATA(fixture_name) *self, \
 		const FIXTURE_VARIANT(fixture_name) *variant); \
-	TEST_F(fixture_name, test_name) \
+	__TEST_F_IMPL(fixture_name, test_name, -1, TEST_TIMEOUT_DEFAULT) \
 	{ \
 		int status; \
 		const pid_t child = fork(); \
@@ -80,6 +80,10 @@
 			__attribute__((unused)) *variant)
 /* clang-format on */
 
+/* Makes backporting easier. */
+#undef TEST_F
+#define TEST_F(fixture_name, test_name) TEST_F_FORK(fixture_name, test_name)
+
 #ifndef landlock_create_ruleset
 static inline int
 landlock_create_ruleset(const struct landlock_ruleset_attr *const attr,