If error hugepage is not in-use, we can fully recovery from error
by dequeuing it from freelist, so return RECOVERY.
Otherwise whether or not we can recovery depends on user processes,
so return DELAYED.

Dependency:
  "HWPOISON, hugetlb: enable error handling path for hugepage"
Signed-off-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NFengguang Wu <fengguang.wu@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>