thp: remove unused vma parameter from khugepaged_alloc_page

The "vma" parameter to khugepaged_alloc_page() is unused.  It has to
remain unused or the drop read lock 'map_sem' optimisation introduce by
commit 8b1645685acf ("mm, THP: don't hold mmap_sem in khugepaged when
allocating THP") wouldn't be safe.  So let's remove it.

Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c

@@ -2413,8 +2413,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 
 static struct page *
 khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm,
-		       struct vm_area_struct *vma, unsigned long address,
-		       int node)
+		       unsigned long address, int node)
 {
 	VM_BUG_ON_PAGE(*hpage, *hpage);
 
@@ -2481,8 +2480,7 @@ static bool khugepaged_prealloc_page(struct page **hpage, bool *wait)
 
 static struct page *
 khugepaged_alloc_page(struct page **hpage, gfp_t gfp, struct mm_struct *mm,
-		       struct vm_area_struct *vma, unsigned long address,
-		       int node)
+		       unsigned long address, int node)
 {
 	up_read(&mm->mmap_sem);
 	VM_BUG_ON(!*hpage);
@@ -2530,7 +2528,7 @@ static void collapse_huge_page(struct mm_struct *mm,
 		__GFP_THISNODE;
 
 	/* release the mmap_sem read lock. */
-	new_page = khugepaged_alloc_page(hpage, gfp, mm, vma, address, node);
+	new_page = khugepaged_alloc_page(hpage, gfp, mm, address, node);
 	if (!new_page)
 		return;