ocfs2: Remove delete inode vote

Ocfs2 currently does cluster-wide node messaging to check the open state of
an inode during delete. This patch removes that mechanism in favor of an
inode cluster lock which is taken at shared read when an inode is first read
and dropped in clear_inode(). This allows a deleting node to test the
liveness of an inode by attempting to take an exclusive lock.

Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>