mm: madvise allow remove operation for hugetlbfs

mm: madvise allow remove operation for hugetlbfs

Orabug: 21652814

Now that we have hole punching support for hugetlbfs, we can
also support the MADV_REMOVE interface to it.

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(cherry picked from commit 8f787c8989ce599cbf0feb10ecea912d07111439)
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>