mm/x86: remove dead code for hugetlbpage.c

It seems to exist since the old times and never used once.  Remove them.

Link: https://lkml.kernel.org/r/20220525195220.10241-1-peterx@redhat.comSigned-off-by: Peter Xu <peterx@redhat.com>
Acked-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

arch/x86/mm/hugetlbpage.c

@@ -19,44 +19,6 @@
 #include <asm/tlbflush.h>
 #include <asm/elf.h>
 
-#if 0	/* This is just for testing */
-struct page *
-follow_huge_addr(struct mm_struct *mm, unsigned long address, int write)
-{
-	unsigned long start = address;
-	int length = 1;
-	int nr;
-	struct page *page;
-	struct vm_area_struct *vma;
-
-	vma = find_vma(mm, addr);
-	if (!vma || !is_vm_hugetlb_page(vma))
-		return ERR_PTR(-EINVAL);
-
-	pte = huge_pte_offset(mm, address, vma_mmu_pagesize(vma));
-
-	/* hugetlb should be locked, and hence, prefaulted */
-	WARN_ON(!pte || pte_none(*pte));
-
-	page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)];
-
-	WARN_ON(!PageHead(page));
-
-	return page;
-}
-
-int pmd_huge(pmd_t pmd)
-{
-	return 0;
-}
-
-int pud_huge(pud_t pud)
-{
-	return 0;
-}
-
-#else
-
 /*
  * pmd_huge() returns 1 if @pmd is hugetlb related entry, that is normal
  * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry.
@@ -72,7 +34,6 @@ int pud_huge(pud_t pud)
 {
 	return !!(pud_val(pud) & _PAGE_PSE);
 }
-#endif
 
 #ifdef CONFIG_HUGETLB_PAGE
 static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file,