Fix check_stdlib_usage.py libc call matching

It now matches libc usage inside statements,
and skips libc-like usage in strings or as struct members.

src/camera/pipewire/SDL_camera_pipewire.c

@@ -330,7 +330,7 @@ static struct param *param_add(struct spa_list *params,
         id = SPA_POD_OBJECT_ID(param);
     }
 
-    p = malloc(sizeof(*p) + (param != NULL ? SPA_POD_SIZE(param) : 0));
+    p = malloc(sizeof(*p) + (param != NULL ? SPA_POD_SIZE(param) : 0)); // This should NOT be SDL_malloc()
     if (p == NULL)
         return NULL;
 
@@ -950,7 +950,7 @@ static void hotplug_registry_global_callback(void *object, uint32_t id,
         g->permissions = permissions;
         g->props = props ? PIPEWIRE_pw_properties_new_dict(props) : NULL;
         g->proxy = proxy;
-        g->name = strdup(name);
+        g->name = strdup(name); // This should NOT be SDL_strdup()
         spa_list_init(&g->pending_list);
         spa_list_init(&g->param_list);
         spa_list_append(&hotplug.global_list, &g->link);