staging: lustre: Remove typedef and update cfs_hash_lock union

Remove typedef keyword and rename the cfs_hash_lock_t
union to cfs_hash_lock in libcfs_hash.h. These changes
resolve the "Do not add new typedefs" warning
generated by checkpatch.pl and meet kernel coding style.

The union variables in hash.c are updated to reflect this
change as well.

Signed-off-by: Lisa Nguyen <lisa@xenapiadmin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>