mm/migrate: remove redundant variables used in a for-loop

The variable addr is being set and incremented in a for-loop but not
actually being used.  It is redundant and so addr and also variable
start can be removed.

Link: https://lkml.kernel.org/r/20211221185729.609630-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c

@@ -2481,8 +2481,7 @@ static bool migrate_vma_check_page(struct page *page)
 static void migrate_vma_unmap(struct migrate_vma *migrate)
 {
 	const unsigned long npages = migrate->npages;
-	const unsigned long start = migrate->start;
-	unsigned long addr, i, restore = 0;
+	unsigned long i, restore = 0;
 	bool allow_drain = true;
 
 	lru_add_drain();
@@ -2528,7 +2527,7 @@ static void migrate_vma_unmap(struct migrate_vma *migrate)
 		}
 	}
 
-	for (addr = start, i = 0; i < npages && restore; addr += PAGE_SIZE, i++) {
+	for (i = 0; i < npages && restore; i++) {
 		struct page *page = migrate_pfn_to_page(migrate->src[i]);
 
 		if (!page || (migrate->src[i] & MIGRATE_PFN_MIGRATE))