mm/list_lru: don't export list_lru_add

It's no longer used by any module, just remove it.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Kairui Song <[e-mail]>
Reviewed-by: Muchun Song <[e-mail]>
Acked-by: Shakeel Butt <[e-mail]>
Cc: Chengming Zhou <[e-mail]>
Cc: Johannes Weiner <[e-mail]>
Cc: Matthew Wilcox (Oracle) <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Qi Zheng <[e-mail]>
Cc: Roman Gushchin <[e-mail]>
Cc: Waiman Long <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/list_lru.c

···
 	spin_unlock(&nlru->lock);
 	return false;
 }
-EXPORT_SYMBOL_GPL(list_lru_add);
 
 bool list_lru_add_obj(struct list_lru *lru, struct list_head *item)
 {