samples/landlock: Fix path_list memory leak

Clang static analysis reports this error

sandboxer.c:134:8: warning: Potential leak of memory
  pointed to by 'path_list'
        ret = 0;
              ^
path_list is allocated in parse_path() but never freed.

Signed-off-by: Tom Rix <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Cc: [email protected]
Signed-off-by: Mickaël Salaün <[email protected]>

samples/landlock/sandboxer.c

@@ -134,6 +134,7 @@ static int populate_ruleset(
 	ret = 0;
 
 out_free_name:
+	free(path_list);
 	free(env_path_name);
 	return ret;
 }