ocfs2: Create the lock status block union.

Wrap the lock status block (lksb) in a union.  Later we will add a union
element for the fs/dlm lksb.  Create accessors for the status and lvb
fields.

Other than a debugging function, dlmglue.c does not directly reference
the o2dlm locking path anymore.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>