mmc: drop nth_page() usage within SG entry

mmc: drop nth_page() usage within SG entry

It's no longer required to use nth_page() when iterating pages within a
single SG entry, so let's drop the nth_page() usage.

Link: https://lkml.kernel.org/r/20250901150359.867252-30-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Lars Persson <lars.persson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>