[RESEND PATCH 1/4 v3] mm: correct return value of migrate_pages() and migrate_huge_pages()

migrate_pages() should return number of pages not migrated or error code. When unmap_and_move return -EAGAIN, outer loop is re-execution without initialising nr_failed. This makes nr_failed over-counted. So this patch correct it by initialising nr_failed in outer loop. migrate_huge_pages() is

[RESEND PATCH 1/4 v3] mm: correct return value of migrate_pages() and migrate_huge_pages()

migrate_pages() should return number of pages not migrated or error code. When unmap_and_move return -EAGAIN, outer loop is re-execution without initialising nr_failed. This makes nr_failed over-counted. So this patch correct it by initialising nr_failed in outer loop. migrate_huge_pages() is