fs/proc/task_mmu: convert smaps_hugetlb_range() to work on folios

fs/proc/task_mmu: convert smaps_hugetlb_range() to work on folios

Let's get rid of another page_mapcount() check and simply use
folio_likely_mapped_shared(), which is precise for hugetlb folios.

While at it, use huge_ptep_get() + pte_page() instead of ptep_get() +
vm_normal_page(), just like we do in pagemap_hugetlb_range().

No functional change intended.

Link: https://lkml.kernel.org/r/20240417092313.753919-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>