From Rohit Seth

1) Bug fixes (mainly in the unsuccessful attempts of hugepages).

   i) not modifying the value of key for unsuccessful key
      allocation

   ii) Correct usage of mmap_sem in free_hugepages

   iii) Proper unlocking of key->lock for partial hugepage
        allocations


2) Include the IPC_LOCK for permission to use hugepages via the
   syscall interface.  This brings the syscall interface into line with
   the hugetlbfs interface.

   It also adds permits users who are in the superuser group to
   access hugetlb resources.  This is so that database servers can run
   without elevated permissions.

3) Increment the key_counts during forks to correctly identify the
   number of processes references a key.