mm: export remove_from_page_cache() to modules

This is needed to enable moving pages into the page cache in fuse with
splice(..., SPLICE_F_MOVE).

Signed-off-by: Miklos Szeredi <[e-mail]>

mm/filemap.c

···
 	spin_unlock_irq(&mapping->tree_lock);
 	mem_cgroup_uncharge_cache_page(page);
 }
+EXPORT_SYMBOL(remove_from_page_cache);
 
 static int sync_page(void *word)
 {