microblaze: add missing pgtable_page_ctor/dtor calls

It will fix NR_PAGETABLE accounting. It's also required if the arch is
going ever support split ptl.

Signed-off-by: Kirill A. Shutemov <[e-mail]>
Cc: Michal Simek <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/microblaze/include/asm/pgalloc.h

···
 #endif
 
 	ptepage = alloc_pages(flags, 0);
-	if (ptepage)
-		clear_highpage(ptepage);
+	if (!ptepage)
+		return NULL;
+	clear_highpage(ptepage);
+	if (!pgtable_page_ctor(ptepage)) {
+		__free_page(ptepage);
+		return NULL;
+	}
 	return ptepage;
 }
 
···
 	__free_page(ptepage);
 }
 
-extern inline void pte_free(struct mm_struct *mm, struct page *ptepage)
+static inline void pte_free(struct mm_struct *mm, struct page *ptepage)
 {
+	pgtable_page_dtor(ptepage);
 	__free_page(ptepage);
 }