userfaultfd: hugetlbfs: fix add copy_huge_page_from_user for hugetlb userfaultfd...

userfaultfd: hugetlbfs: fix add copy_huge_page_from_user for hugetlb userfaultfd support

Orabug: 21685254

Was in Andrew's patch series on January 17, 2017 as:
userfaultfd hugetlbfs fix __mcopy_atomic_hugetlb retry error processing fix fix

kunmap() takes a page*, per Hugh

Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Ported to UEK ]
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Dhaval Giani <dhaval.giani@oracle.com>
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>