ANDROID: vendor_hook: Add hook in __free_pages()

This reverts commit eb99e6d80ee21eb061c55cdf14c0b05e0c61af4d

The hook android_vh_free_pages is deleted, due to the symbol is
not added to the abi list. The symbol is added to the abi list in
patch:2183484. This patch is to add the hook android_vh_free_pages
again.

Bug: 234214858
Bug: 203756332
Cc: Greg Kroah-Hartman <gregkh@google.com>
Signed-off-by: Bing Han <bing.han@transsion.com>
Change-Id: I2c97ea4d310e2004b94d891678127c17f7b07c93
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9e43e2b..d2b7eca 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5183,6 +5183,7 @@ static inline void free_the_page(struct page *page, unsigned int order)
 
 void __free_pages(struct page *page, unsigned int order)
 {
+	trace_android_vh_free_pages(page, order);
 	if (put_page_testzero(page))
 		free_the_page(page, order);
 	else if (!PageHead(page))