mm/memcg: drop swp_entry_t* in mc_handle_file_pte()

It is unused after the rework of commit f5df863 ("mm: use
find_get_incore_page in memcontrol").

Link: https://lkml.kernel.org/r/20210916193014.80129-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

@@ -5545,7 +5545,7 @@ static struct page *mc_handle_swap_pte(struct vm_area_struct *vma,
 #endif
 
 static struct page *mc_handle_file_pte(struct vm_area_struct *vma,
-			unsigned long addr, pte_t ptent, swp_entry_t *entry)
+			unsigned long addr, pte_t ptent)
 {
 	if (!vma->vm_file) /* anonymous vma */
 		return NULL;
@@ -5718,7 +5718,7 @@ static enum mc_target_type get_mctgt_type(struct vm_area_struct *vma,
 	else if (is_swap_pte(ptent))
 		page = mc_handle_swap_pte(vma, ptent, &ent);
 	else if (pte_none(ptent))
-		page = mc_handle_file_pte(vma, addr, ptent, &ent);
+		page = mc_handle_file_pte(vma, addr, ptent);
 
 	if (!page && !ent.val)
 		return ret;