samples/landlock: Bump ABI version to 8

The sample tool should print a warning if it is not running on a
kernel that provides the newest Landlock ABI version.

Link: https://lore.kernel.org/all/[email protected]/
Suggested-by: Mickaël Salaün <[email protected]>
Signed-off-by: Günther Noack <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Mickaël Salaün <[email protected]>

Author: gnoack

samples/landlock/sandboxer.c

@@ -299,7 +299,7 @@ static bool check_ruleset_scope(const char *const env_var,
 
 /* clang-format on */
 
-#define LANDLOCK_ABI_LAST 7
+#define LANDLOCK_ABI_LAST 8
 
 #define XSTR(s) #s
 #define STR(s) XSTR(s)
@@ -436,7 +436,8 @@ int main(const int argc, char *const argv[], char *const *const envp)
 		/* Removes LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON for ABI < 7 */
 		supported_restrict_flags &=
 			~LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON;
-
+		__attribute__((fallthrough));
+	case 7:
 		/* Must be printed for any ABI < LANDLOCK_ABI_LAST. */
 		fprintf(stderr,
 			"Hint: You should update the running kernel "