mm: hugetlbfs: use __compound_tail_refcounted in __get_page_tail too

mm: hugetlbfs: use __compound_tail_refcounted in __get_page_tail too

Also remove hugetlb.h which isn't needed anymore as PageHeadHuge is
handled in mm.h.

Signed-off-by: Andrea Arcangeli <[email protected]>
Cc: Khalid Aziz <[email protected]>
Cc: Pravin Shelar <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Ben Hutchings <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Minchan Kim <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>